Heat Wave Period Research Articles

Estimation of thermal comfort felt by human exposed to extreme heat wave in a complex urban area using a WRF-MENEX model.

Thermal comfort could indicate human thermal sensation when exposed to a local meteorological condition. Because humans can suffer illness when exposed to heat or even die, it is essential to assess human comfort levels to increased temperature and to provide this information to the public. This study aims to estimate thermal comfort using the human heat balance model combined with a numerical meteorological model in Seoul mega city during the heat wave periods experienced during 2016. The gridded thermal comfort index of physiological subjective temperature (PST) was calculated based on the Man-Environment Heat Exchange (MENEX) model, which used as inputs the meteorological parameters, clothing insulations, and metabolic rates. High-resolution meteorological parameters were obtained by coupling Weather Research and Forecasting (WRF) model with Building Effect Parameterization (BEP) + Building Energy Model (BEM) using detailed urban classification. The modeling results showed that the PST distribution has a clearly heterogeneous spatial distribution during the heat wave period. The high PST values were largely found in the residential area during the day, due to the high temperature and low wind speed associated with high-density buildings, and the daily maximum PST reached a very hot level (44.1-54.0°C). Our study suggested that the human heat balance model combined with the numerical meteorological model could be used to provide more reliable information about thermal comfort to groups that may be vulnerable to the effects of heat waves in complex urban environments.

Assessment of Indoor Environmental Quality for Retrofitting Classrooms with An Egg-Crate Shading Device in A Hot Climate

In the Mediterranean climate, a large number of educational buildings suffer from discomfort due mostly to energy-deficient thermal envelopes and a lack of cooling systems. Impending climate change is expected to worsen overheating in classrooms, especially during heatwave periods. Therefore, the protection of window openings to reduce incident solar radiation while maintaining adequate indoor environmental quality must be considered a necessary key focus. The main objective of this research is to assess the influence of an egg-crate shading device on the indoor environmental quality of a classroom in Southern Spain. To do so, two classrooms—with and without this shading device—were simultaneously monitored over a whole year. The implementation of an egg-crate shading device allowed for a significant reduction of the incident solar radiation, both in summer and mid-season (around 45–50%), which objectively slightly conditioned indoor operative temperatures. Given the noticeable influence of the user patterns observed, indoor illuminance was also improved, as the rolling shutters tended to be opened at higher aperture levels.

Spatio -temporal variations in urban heat island and its interaction with heat wave

Most of the urban localities are facing the effects of Urban Heat Island (UHI) and extreme heat wave (HW) events. It is expected that these HW events are likely to be intensified by the effect of UHI in the future. As these events project to increase in both severity and frequency therefore, it is crucial to assess the intensity of UHI and examine the relationship between HW and UHI. In this study, observations for different coastal areas are used to quantify the impacts of UHI during the HW events. The spatial and temporal variability patterns of UHI in the metropolitan city of Karachi were also investigated using hourly temperature observations for a period of 10 years in two phases (a) from 1998 to 2002 (b) from 2012 to 2016. During the first phase (1998–2001), the maximum Urban Heat Island Intensity (UHII) for night time in summer was 1.9 °C, while during the second phase (2012–2016), it increased by 0.6 °C. Despite the fact that both phases have shown similar pattern for seasonal UHII, urban-rural temperature difference was found to be significant in summer especially in the night time. Temporal distribution of UHII for winter shows that average intensity of UHI during daytime varies between 0.1 °C and 3.2 °C, considering the overall time duration. The results indicate that UHII increased significantly during the HW period which caused more than 800 deaths in Karachi between 17th June and 24th June 2015.

Analysis on influencing factors of deaths from severe heat stroke in Shanghai, 2013-2017

Objective: To explore the related factors of death from severe heat stroke in Shanghai from 2013 to 2017. Methods: The data of 1 152 patients with severe heat stroke who were divided into survival (n=1 037) and death (n=115) groups including gender, age and heat stroke type (heat cramp, heat exhaustion, heat apoplexy and the mixed type) were collected from meteorological bureau and case report system for high temperature heat stroke in Shanghai from 2013 to 2017. Meanwhile, the meteorological data of the onset date of severe heat stroke cases were collected, including maximum temperature, minimum temperature, daily temperature, relative humidity, air pressure, precipitation and wind speed. The differences of individual and meteorological factors between the two groups were compared, and multivariate logistic regression model was used to analyze the related factors of death from severe heat stroke. Results: Among 1 152 cases, the mean±SD of age was (56.29±18.95) years old, 843 (73.18%)were male, 962 (83.51%) were in the heat wave period; 322 cases (27.95%) were heat cramp, 170 cases (14.76%) were heat exhaustion, 533 cases (46.27%) were heat apoplexy and 114 cases (9.90%) were the mixed type. Daily average temperature ((32.81±1.99) ℃), daily maximum and minimum temperatures ((38.20±2.24) ℃ and (29.22±1.94) ℃) in survival group were lower than those in death group (all P values<0.001), which were (33.76±1.17) ℃, (39.19±1.31) ℃ and (29.72±1.66) ℃. Daily average relative humidity ((60.36±9.75)%) and daily minimum relative humidity ((41.26±9.71)%) in survival group were higher than those in death group(allP values <0.05), which were (54.59±6.89)% and (35.60±7.24)%. The results of logistic regression analysis suggested that compared with the cases with daily average humidity <60% and a mixed type heat stroke, the death OR (95%CI) values of cases with daily average humidity >60%, heat cramp, heat exhaustion and heat apoplexy were 0.31 (0.18,0.54), 0.13 (0.05,0.34), 0.68 (0.58,2.30) and 0.87 (0.48,1.58). Conclusion: The temperature, relative humidity and the type of heat stroke were the main related factors affecting the prognosis of severe heat stroke.

Investigating local climate zones for outdoor thermal comfort assessment in an Indian city

The rapid growth of development and urbanization in the Indian subcontinents has made the urban areas vulnerable to outdoor thermal discomfort (OTC) which is in turn affecting the quality of living in these areas. This study aims at evaluating spatiotemporal dynamics of outdoor thermal comfort in Nagpur city (India) during winter, summer and heat wave period using Local Climate Zone (LCZ) classification. It uses Thom's Discomfort Index (DI) and Relative Strain Index (RSI) to analyze outdoor thermal comfort. It also examines the significance of major LCZs in addressing thermal anomaly and OTC at different time periods using One-way ANOVA technique. It identifies critical LCZ having a maximum exposure of discomfort and concludes with the applicability of LCZ for addressing discomfort.

Influence of Heat Waves on Daily Hospital Visits for Mental Illness in Jinan, China-A Case-Crossover Study.

Background: Given that more frequent and intensive extreme heat events have been projected based on climate change modeling, it is of significance to have a better understanding of the association between heat waves and mental illnesses. This study aimed to explore the effects of heat waves on daily hospital visits for mental illness in the summer of 2010 in Jinan, China. Methods: A symmetric bidirectional case-crossover study was firstly conducted to determine the relationship between daily hospital visits for mental illness and heat waves in Jinan in 2010. Multifactor logistic regression analysis was then used to analyze the influencing factors for daily hospital visits for mental illness during the heat wave periods. Results: Multivariable analysis showed that the heat wave events were associated with an increased risk of mental illness. The largest odds ratios (ORs) of the heat waves for daily hospital visits for mental illness were 2.231 (95% confidence interval (CI): 1.436–3.466) at a 3-day lag, 2.836 (95% CI: 1.776–4.525) at a 2-day lag, 3.178 (95% CI: 1.995–5.064) at a 3-day lag, and 2.988 (95% CI: 2.158–4.140) at a 2-day lag for the first, second, third, and fourth heat waves, respectively. The elderly, urban residents, outdoor workers, and singles may be high-risk populations for developing heat wave-related mental illness. Conclusions: Our study has supported that there is a positive association between heat waves and hospital visits for mental illness in the study site. Age, home address, occupation, and marital status were associated with daily hospital visits for mental illness during the heat wave periods.

Evaluation of the French reactive mortality surveillance system supporting decision making.

In France, a mortality syndromic surveillance system was set up with objectives of early detection and reactive evaluation of the impact of expected and unexpected events to support decision makers. This study aims to describe the characteristics of the system and its usefulness for decision makers. Anonymized data from the administrative part of death certificates were daily collected from 3062 computerized city halls and were transmitted to Santé publique France in routine. Coverage of the system was measured as the proportion of deaths registered by the system among the complete number of deaths and analyzed by age, month and region. Deaths were described by gender, age and geographical level using proportion. The excess periods of deaths were described based on the comparison of the weekly observed and expected numbers of deaths between 2012 and 2016. The system recorded 77.5% of the national mortality covering the whole territory. About 81% of deaths were aged 65 years old and more. The surveillance system identified mortality variations mainly during winter and summer, for some concomitant with influenza epidemic or heatwave period, and thus provided information for decision makers. The ability of the system to detect and follow mortality outbreaks in routine in the whole territory has been demonstrated. It is a useful tool to provide early evaluation of the impact of threats on mortality and alert decision makers to adapt control measures. However, the absence of information on medical causes of death may limit the ability to target recommendations.

Modelling extreme peak electricity demand during a heatwave period: a case study

A frequency analysis of the occurrence of extreme peak electricity demand during the non-winter period using South African data for the period 2007–2013 is discussed in this paper. It is during the non-winter period when Eskom, South Africa’s power utility company usually carries out its maintenance of power plants. Extreme peak loads together with high unplanned and planned outages usually cause disruptions to the power plants’ maintenance programmes during this period. A detailed analysis of peak electricity demand is useful to maintain the stability of the power grid. If not properly managed this may result in negative economic impacts as electricity is one of the major drivers of any economy. Initially the data is detrended using a time-varying threshold. A sufficiently high threshold is obtained by using bounded corrected extremal mixture models. We then decluster the exceedances and fit a peaks-over-threshold model to cluster maxima. Empirical results show that demand of electricity significantly increases as a result of heat which builds up with consecutive days of extreme high temperatures. The main contribution of this paper is in the application of extreme value theory models in assessing the frequency of occurrence of extreme peak loads to assist power utilities in the planning of maintenance of generating units. The other contribution is in the development of a modelling framework which shows that as temperature converges to its upper bound, the marginal increase of electricity demand also converges. Most of the cluster maxima are experienced during the months October, November and February, suggesting that these may not be good months for scheduling maintenance of generating plants during the non-winter period in South Africa. This modelling approach may help system operators in scheduling and dispatching of electricity during the heatwave period.

A Two-Decade Anthropogenic and Biogenic Isoprene Emissions Study in a London Urban Background and a London Urban Traffic Site

A relationship between isoprene and 1,3-butadiene mixing ratios was established to separate the anthropogenic and biogenic fractions of the measured isoprene in London air in both urban background (Eltham) and urban traffic (Marylebone Road) areas over two decades (1997–2017). The average daytime biogenic isoprene mixing ratios over this period reached 0.09 ± 0.04 ppb (Marylebone Road) and 0.11 ± 0.06 ppb (Eltham) between the period of 6:00 to 20:00 local standard time, contributing 40 and 75% of the total daytime isoprene mixing ratios. The average summertime biogenic isoprene mixing ratios for 1997–2017 are found to be 0.13 ± 0.02 and 0.15 ± 0.04 ppb which contribute 50 and 90% of the total summertime isoprene mixing ratios for Marylebone Road and Eltham, respectively. Significant anthropogenic isoprene mixing ratios are found during night-time (0.11 ± 0.04 ppb) and winter months (0.14 ± 0.01 ppb) at Marylebone Road. During high-temperature and high-pollution events (high ozone) there is a suggestion that ozone itself may be directly responsible for some of the isoprene emission. By observing the positive correlation between biogenic isoprene levels with temperature, photosynthetically active radiation and ozone mixing ratios during heatwave periods, the Cobb-Douglas production function was used to obtain a better understanding of the abiotic factors that stimulate isoprene emission from plants. Other reasons for a correlation between ozone and isoprene are discussed. The long-term effects of urban stressors on vegetation were also observed, with biogenic isoprene mixing ratios on Marylebone Road dropping over a 20-year period regardless of the sustained biomass levels.

Characterizing the atmospheric conditions during the 2010 heatwave in Rio de Janeiro marked by excessive mortality rates

Global temperatures have increased considerably over the last decades, directly impacting the number, intensity and duration of extreme events such as heat waves. Climate model projections accounting for anthropogenic factors indicate that deadly mega-heat waves are likely to become more frequent in the future. Although the atmospheric features and social-economic related impacts of heat waves have already been documented in various regions around the world, for other highly populated regions, such as the Metropolitan Region of Rio de Janeiro (MRRJ), a similar objective assessment is still needed. Heat waves directly impact the public health sector and particularly the less wealthy and elderly population groups. During February 2010, an elevated mortality peak occurred during a 8-day period (from 2 to 9 Feb 2010) characterized as a heat wave episode in MRRJ. A total excess of 737 deaths was recorded with the elderly group registering the highest mortality incidence. During this heat wave period, a quasi-stationary anticyclonic anomaly forced in altitude by a Rossby wave train was established over the south Brazilian coast. At the surface, the meteorological scenario from January 2010 to the heat wave period was marked by clear sky conditions, large precipitation deficits, and enhanced diabatic heating. During the heat wave period, warm and dry air masses were advected from interior regions towards the MRRJ, exacerbating temperature conditions by pronounced subsidence and adiabatic heating mechanisms. All these conditions contributed to pronounced positive temperature anomalies, reinforced by land-atmosphere feedbacks.

Is the urban heat island exacerbated during heatwaves in southern Australian cities?

The extra-tropical Australian cities of Melbourne, Adelaide, and Perth are all affected by summer heatwaves and the urban heat island (UHI) effect. While research has been undertaken on both phenomena individually, they have not been studied in tandem in Australia. This research investigates the relationship between warm season heatwaves (November to March) and the UHI from January 1995 to March 2014. Observational temperature data from six or seven Bureau of Meteorology Automatic Weather Stations in each of Melbourne, Adelaide, and Perth are used to determine the strength of the UHI during heatwave periods and these are compared to non-heatwave periods. Melbourne and Adelaide both experience an exacerbated (warmer than normal) UHI at night during heatwaves. The night-time UHI in Perth is diminished (cooler than normal) during heatwaves and often changes to an urban cool island (UCI), when compared to non-heatwave periods. Environmental factors that might affect the strength of the UHI are investigated, including wind speed and direction, and station location. Despite the proximity of all stations to the coast, coastal influences on UHI strength are minimal during heatwave conditions. Station choice is found to not affect our results, with the characteristic pattern of the UHI during heatwaves remaining consistent across all three cities in a leave-one-out sensitivity analysis.

The abrupt increase in the Aegean sea surface temperature during June 2007 – a marine heatwave event?

AbstractIn this article we examine the abrupt increase in the Aegean Sea (southeast Mediterranean) surface temperature (SST) during the heatwave of June 2007 and the associated synoptic conditions. Air temperature and wind speed meteorological data, along with SST reanalysis data and combined satellite image and model data, are used. The analysis shows an unusual and very rapid rise in SST for the Aegean Sea and eastern Mediterranean area for the period 22 June to 2 July 2007, indicating the possible occurrence of a marine heatwave event. The average SST value for June 2007 was found to be of the order of +5 degC above the month's normal climatic average. The available data support the hypothesis that the cause of these anomalies was a combination of the passive response of the Aegean Sea surface to radiation flux anomalies during the June 2007 heatwave period and the prevailing low wind speed conditions.

A reactive mortality surveillance system in France for alert and decision-making

Background In France, after the 2003 heat wave, a mortality syndromic surveillance system was set up by the National Public Health Agency, with objectives of early detection and reactive evaluation of the impact of expected and unexpected events to support decision makers. This study aims to describe the characteristics of the system and the main excess mortality period detected by the system since 2011 that led to alert decision makers for actions. Methods Anonymized data from the administrative part of death certificate were daily collected from 3042 computerized city halls and were transmitted to the agency in routine. Representativeness was measured as the proportion of death registered by the system among the exhaustive number of deaths and analyzed by age, month and region. Deaths were described by gender, age group at national and regional levels using proportion. Mortality surveillance is performed routinely based on the comparison of the weekly observed and expected number of deaths estimated with the model developed by the European consortium EuroMomo between 2012 and 2016. Based on criteria, when an excess of death is observed, decision makers are alerted and an investigation is launched. Results The system recorded 77.5% of the national mortality covering the whole territory and varying from 67% to 96.8% in metropolitan regions and overseas. Three major excess deaths episodes occurred during winters 2011–12, 2012–13 and 2014–15 and were highly correlated with flu epidemics periods. Five punctual excess periods were identified during the summer months, among them 4 were concomitant with a heat wave or elevated temperature period. No particular event was found correlated to the fifth excess. The system was also able to detect events such as an increase in mortality in Guadeloupe in 2014 concomitant with chikungunya epidemics. National and regional epidemiological mortality reports were published weekly (daily if required) and transmitted to the Ministry of Health and regional health authorities with potential recommendations. Conclusion The effectiveness of the reactive mortality surveillance system to alert decision makers has been demonstrated. It is useful to adapt along the event recommendation for control measures as well as evaluation of impact of the event on mortality. However, the absence of medical causes of death may limit the ability to target recommendations. Facing the challenge of emergence of epidemics and climate changes, this reactive mortality system will be complementary for other surveillance systems for the future health crisis. The development of mortality surveillance with causes of death will ensure more information for interpretation of all-cause mortality changes.

The Impact of Heat Waves on Emergency Department Admissions in Charlottesville, Virginia, U.S.A.

Heat waves have been linked to increases in emergency-related morbidity, but more research is needed on the demographic and disease-specific aspects of these morbidities. Using a case-crossover approach, over 700,000 daily emergency department hospital admissions in Charlottesville, Virginia, U.S.A. from 2005–2016 are compared between warm season heat wave and non-heat wave periods. Heat waves are defined based on the exceedance, for at least three consecutive days, of two apparent temperature thresholds (35 °C and 37 °C) that account for 3 and 6% of the period of record. Total admissions and admissions for whites, blacks, males, females, and 20–49 years old are significantly elevated during heat waves, as are admissions related to a variety of diagnostic categories, including diabetes, pregnancy complications, and injuries and poisoning. Evidence that heat waves raise emergency department admissions across numerous demographic and disease categories suggests that heat exerts comorbidity influences that extend beyond the more well-studied direct relationships such as heat strokes and cardiac arrest.

The effects of increasing surface reflectivity on heat-related mortality in Greater Montreal Area, Canada

Heat-related mortality is increasing as the result of climate change, extreme heat events and higher ambient temperature because of urban heat island (UHI) phenomenon. We coupled the Weather Research and Forecasting model (WRFV3.6.1) with a multi-layer of the Urban Canopy Model (ML-UCM) to investigate the effects of UHI intensity during the 2005 and 2011 heat wave periods in Greater Montreal Area (GMA), Canada. Each day of simulation is categorized into an air mass type using the Spatial Synoptic Classification. Using the non-accidental mortality data during summer period, the number of deaths above the expected mean anomalous daily mortality is calculated for each air mass classification. Results indicate that moist tropical plus and dry tropical weather have the highest rank in heat-related death. We assessed the effects of increasing surface reflectivity (ISR) on four meteorological parameters: 2-m air temperature, 10-m wind speed, 2-m relative humidity, dew point temperature, and four heat stress indices: National Weather Service – Heat Index, Apparent Temperature, Canadian Humid Index, and Discomfort Index (DI). ISR decreased air temperature by 0.6 °C, increased relative humidity by 2%, increased dew point temperature by 0.4 °C. The DI improved by 3% and heat-related mortality decreased by nearly 3.2% during heat wave periods in GMA.

Reduction in baseline corticosterone secretion correlates with climate warming and drying across wild lizard populations.

Climate change should lead to massive loss of biodiversity in most taxa, but the detailed physiological mechanisms underlying population extinction remain largely elusive so far. In vertebrates, baseline levels of hormones such as glucocorticoids (GCs) may be indicators of population state as their secretion to chronic stress can impair survival and reproduction. However, the relationship between GC secretion, climate change and population extinction risk remains unclear. In this study, we investigated whether levels of baseline corticosterone (the main GCs in reptiles) correlate with environmental conditions and associated extinction risk across wild populations of the common lizard Zootoca vivipara. First, we performed a cross-sectional comparison of baseline corticosterone levels along an altitudinal gradient among 14 populations. Then, we used a longitudinal study in eight populations to examine the changes in corticosterone levels following the exposure to a heatwave period. Unexpectedly, baseline corticosterone decreased with increasing thermal conditions at rest in females and was not correlated with extinction risk. In addition, baseline corticosterone levels decreased after exposure to an extreme heatwave period. This seasonal corticosterone decrease was more pronounced in populations without access to standing water. We suggest that low basal secretion of corticosterone may entail downregulating activity levels and limit exposure to adverse climatic conditions, especially to reduce water loss. These new insights suggest that rapid population decline might be preceded by a downregulation of the corticosterone secretion.

The Effect of Increasing Surface Albedo on Urban Climate and Air Quality: A Detailed Study for Sacramento, Houston, and Chicago

Increasing surface reflectivity in urban areas can decrease ambient temperature, resulting in reducing photochemical reaction rates, reducing cooling energy demands and thus improving air quality and human health. The weather research and forecasting model with chemistry (WRF-Chem) is coupled with the multi-layer of the urban canopy model (ML-UCM) to investigate the effects of surface modification on urban climate in a two-way nested approach over North America focusing on Sacramento, Houston, and Chicago during the 2011 heat wave period. This approach decreases the uncertainties associated with scale separation and grid resolution and equip us with an integrated simulation setup to capture the full impacts of meteorological and photochemical reactions. WRF-ChemV3.6.1 simulated the diurnal variation of air temperature reasonably well, overpredicted wind speed and dew point temperature, underpredicted relative humidity, overpredicted ozone and nitrogen dioxide concentrations, and underpredicted fine particular matters (PM2.5). The performance of PM2.5 is a combination of overprediction of particulate sulfate and underprediction of particulate nitrate and organic carbon. Increasing the surface albedo of roofs, walls, and pavements from 0.2 to 0.65, 0.60, and 0.45, respectively, resulted in a decrease in air temperature by 2.3 °C in urban areas and 0.7 °C in suburban areas; a slight increase in wind speed; an increase in relative humidity (3%) and dew point temperature (0.3 °C); a decrease of PM2.5 and O3 concentrations by 2.7 µg/m3 and 6.3 ppb in urban areas and 1.4 µg/m3 and 2.5 ppb in suburban areas, respectively; minimal changes in PM2.5 subspecies; and a decrease of nitrogen dioxide (1 ppb) in urban areas.

Outpatient clinic visits during heat waves: findings from a large family medicine clinical database.

The purpose of this study was to determine whether heat waves are associated with increased frequency of clinic visits for ICD-9 codes of illnesses traditionally associated with heat waves. During 4 years of family medicine clinic data between 2012 and 2016, we identified six heat wave events in San Diego County. For each heat wave event, we selected a control period in the same season that was twice as long. Scheduling a visit on a heat wave day (versus a non-heat wave day) was the primary predictor, and receiving a primary ICD-9 disease code related to heat waves was the outcome. Analyses were adjusted for age, gender, race/ethnicity and marital status. Of the 5448 visits across the heat wave and control periods, 6.4% of visits (n = 346) were for heat wave-related diagnoses. Scheduling a visit on heat wave day was not associated with receiving a heat wave-related ICD code as compared with the control period (adjusted odds ratio: 1.35; 95% confidence interval: 0.86-1.36; P = 0.51). We show that in a relatively large and demographically diverse population, patients who schedule appointments during heat waves are not being more frequently seen for diagnoses typically associated with heat waves in the acute setting. Given that heat waves are increasing in frequency due to climate change, there is an opportunity to increase utilization of primary care clinics during heat waves.

Assessment of Heatwave Impacts on Cause-Specific Emergency Department Attendances in Queensland, Australia

Background/Aim: To examine the impacts of heatwaves on emergency department attendances (EDAs) in Queensland, Australia. Methods: A quasi-Poisson generalized additive model was used to quantify the effects of heatwaves on cause-specific EDAs in eight cities of Queensland, Australia, including Brisbane, Cairns, Longreach, Mackay, Mount Isa, Rockhampton, Toowoomba and Townsville. The study period was from 01/01/2013 to 31/12/2015. Possible confounders including seasonality and long-term trend, day of week, and relative humidity were controlled in the model. The city-specific results were meta-analyzed to get the pooled result for the whole Queensland. Based on the findings of our previous work, heatwave was defined as three or more consecutive days when the mean temperature was ≥ 95th percentile of the mean temperature across the whole study period. Results: During heatwave periods, EDAs for a wide range of diseases increased appreciably in Queensland, including nutritional and metabolic diseases (RR:1.181, 95% CI:1.040, 1.342), injury, poisoning and certain other consequences of external causes (RR:1.092, 95% CI:1.039,1.147), diseases of the nervous system (RR:1.091, 95% CI:1.021, 1.166), diseases of the skin and subcutaneous tissue (RR:1.079, 95% CI:1.002, 1.162), diseases of the musculoskeletal system and connective tissue (RR:1.069, 95% CI:1.004, 1.140), endocrine, mental and behavioral disorders (RR:1.062, 95% CI:1.006, 1.120), certain infectious and parasitic diseases (RR:1.058, 95% CI:1.011, 1.108), diseases of the circulatory system (RR:1.055, 95% CI:1.014,1.097), diseases of the genitourinary system (RR:1.046, 95% CI:1.004, 1.090), and diseases of the ear and mastoid process (RR:1.041, 95% CI:1.006,1.077). Heatwave effects on total EDAs varied across different cities, and the greatest effect was observed in Townsville (RR:1.082, 95% CI:1.026, 1.140), followed by Rockhampton (RR:1.071, 95% CI: 1.024, 1.120), Mount Isa (RR:1.056, 95% CI: 0.975, 1.144), Toowoomba (RR:1.031, 95% CI:0.974, 1.092), Cairns (RR:1.029 , 95% CI:0.991, 1.069), Brisbane (RR:1.018, 95% CI:0.999, 1.038), Mackay (RR:1.016, 95% CI:0.970, 1.063), and Longreach (RR:0.977, 95% CI:0.851, 1.121). The effect of heatwaves on total EDAs in the rural region (RR:1.039, 95% CI:1.010, 1.069) was similar to that in the urban region (RR:1.035, 95% CI:1.003, 1.068). Conclusions: EDAs for a wide range of diseases increased during heatwave periods. As climate change progresses, EDAs in Queensland may increase in the future, requiring the Queensland Government to develop effective public health strategies to adapt to climate change.

Mitigation of heat stress risks through building energy efficiency upgrade: a case study of Melbourne, Australia

People spend most of their time indoor during a heatwave period, as such assessment of indoor heat stress is an important issue for public health care. In this study, the impact of building energy efficiency in mitigating the risks of experiencing heat stress by the occupants different energy-rated dwellings was investigated under the 2009 Melbourne heatwave scenario. First of all, distributions of different energy-rated houses and the percentage of people living in those houses were calculated. Indoor heat stress conditions of the different energy-rated houses were calculated using building simulation software EnergyPlus and two well-established heat stress indices: wet bulb globe temperature and discomfort index. The results showed that residents of 0.9 energy star-rated houses are approximately 50% more vulnerable to experiencing heat stress during a heatwave compared to the residents of 5.4 energy star-rated houses. It was revealed that upgrading energy efficiency of existing dwellings could be one of the most effective heatwave mitigation measures. If the entire lower energy-rated houses can be upgraded to 5.4-star, the percentage of people that are at risk of being exposed to extreme heat stress conditions for 6 h could reduce from 50% to only 4%.