Hot Summer Days Research Articles

Sub-Daily Temperature Heterogeneity in a Side Channel and the Influence on Habitat Suitability of Freshwater Fish

Rising surface water temperatures in fluvial systems increasingly affect biodiversity negatively in riverine ecosystems, and a more frequent exceedance of thermal tolerance levels of species is expected to impoverish local species assemblages. Reliable prediction of the effect of increasing water temperature on habitat suitability requires detailed temperature measurements over time. We assessed (1) the accuracy of high-resolution images of water temperature of a side channel in a river floodplain acquired using a consumer-grade thermal camera mounted on an unmanned airborne vehicle (UAV), and (2) the associated habitat suitability for native and alien fish assemblages. Water surface temperatures were mapped four times throughout a hot summer day and calibrated with 24 in-situ temperature loggers in the water at 0.1 m below the surface using linear regression. The calibrated thermal imagery was used to calculate the potentially occurring fraction (POF) of freshwater fish using species sensitivity distributions. We found high temperatures (25–30 °C) in the side channel during mid-day resulting in reduced habitat suitability. The accuracy of water temperature estimates based on the RMSE was 0.53 °C over all flights (R2 = 0.94). Average daily POF was 0.51 and 0.64 for native and alien fish species in the side channel. The error of the POF estimates is 76% lower when water temperature is estimated with thermal UAV imagery compared to temperatures measured at an upstream gauging station. Accurately quantifying water temperature and the heterogeneity thereof is a critical step in adaptation of riverine ecosystems to climate change. Our results show that measurements of surface water temperature can be made accurately and easily using thermal imagery from UAVs allowing for an improved habitat management, but coincident collection of long wave radiation is needed for a more physically-based prediction of water temperature. Because of climate change, management of riverine ecosystems should consider thermal pollution control and facilitate cold water refugia and connectivity between waterbodies in floodplains and the cooler main channel for fish migration during extremely hot summer periods.

Impact of Maximum Air Temperature on Ambulance Transports Owing to Heat Stroke during Spring and Summer in Tottori Prefecture, Japan

TPS 661: Climate change: temperature effects 1, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: The frequency and intensity of hot weather have increased. In Japan, there have been many studies of the relationship between ambulance transports owing to heat stroke (ATHS) and high air temperature in the summer season. However, there have been very few reports focusing on ATHS in spring. Therefore, we investigated the effect of the maximum air temperature on ATHS not only in summer but also in spring, to help with development of effective measures to prevent heat stroke. Methods: We obtained daily ATHS and meteorological data from April to September in 2017 in Tottori Prefecture. We used a time-stratified case-crossover method for data analysis. Results: A total 382 cases of ATHS were identified from April to September in 2017 in Tottori. The number of cases was highest in July, followed by August and May. Maximum air temperature was significantly linked to ATHS. The risk of ATHS was increased 1.13 times when maximum air temperature rose by 1°C. In summer, the risk on extremely hot days (maximum air temperature ≥ 35°C) increased by 5.55 times or more compared with that on days below 30 °C (< 30°C). The risk was approximately four times greater on hot days (≥ 30°C and < 35°C) than that on relatively cooler days (< 30°C) during the spring months of April through May. Conclusion: Maximum air temperature was significantly linked to ATHS. It is necessary to pay particular attention to heat stroke prevention not only on extremely hot days in summer but also on hot days in the spring.

Evaporation aided improvement for cooling performance of large scale natural draft dry cooling system

The cooling performance of natural draft dry cooling system gets deteriorated at high ambient temperature. In this work, the water spray cooling is proposed to chill the inlet air of air-cooled heat exchanger to improve the cooling performance of natural draft dry cooling system in hot summer days. Based on a typical 600 MW power generating unit, a numerical model coupled the water spray with dry cooling system is developed to evaluate the cooling performance of natural draft dry cooling system with evaporation aided cooling under windless and windy conditions. The results show that the cooling performance gets improved due to water spray evaporation although the total air flow rate decreases. The heat rejection for the leeward sector increases a lot for the conspicuous inlet air temperature drop, but decreases for the windward sectors. The complete evaporation is easier to be achieved near the windward sector, but the evaporation ratio is unfavorable at the wind speed of 8 m/s. The unit back pressure gradually decreases with increasing the spraying flow rate and has an average drop of 3 kPa with a relatively high evaporation ratio at the spraying flow rate of 0.25 kg/s.

Summer high temperature extremes over Northeastern China predicted by spring soil moisture

Current seasonal climate predictions mainly reside in the ocean anomalies. However, the prediction skills are generally limited over many extra-tropical land areas where the oceanic effects are relatively weak. In this study, we address the potential of preceding spring soil moisture condition to predict summer hot days over Northeastern China, a typical Northern Hemisphere mid-latitude region. The results show that spring soil moisture condition over Central-Eastern China is closely related with following summer hot days over Northeastern China for the period of 1979–2017. The statistical model based on the preceding spring soil moisture condition yields temporal cross-validated correlation skill of 0.57 for summer hot days over Northeastern China. The spatial pattern correlation skills of independent hindcast experiments for 2009–2017 are also high, ranging from 0.87 to 0.94. Our results can be easily applied to practical prediction of summer hot days over Northeastern China, and help to provide better climate services and reduce the detrimental effects of extreme heat over this extra-tropical region.

Does temperature variation influence nest box use by the eastern pygmy-possum?

Cavity-using birds and mammals reliant on nest boxes may be negatively affected by the poor thermal buffering of nest boxes. I investigated whether nest box use by the eastern pygmy-possum (Cercartetus nanus) over a 4-year period was influenced by maximum ambient temperature, which ranged from 15.6 to 34.9°C during survey occasions. Occupancy modelling of 144 site detections over 30 survey occasions suggested that a model that included maximum temperature had little support whereas a model involving time-varying detection (i.e. detection differed across sample occasions) was the most plausible. I also investigated how temperatures in nest boxes and tree hollows varied over the four hottest days of summer, including one day when the temperature reached 40.6°C. Maximum temperatures were 3–4°C cooler in plywood nest boxes and 5–8°C cooler in tree hollows compared with ambient temperatures. Together, these results suggest that eastern pygmy-possums using nest boxes in coastal areas are unlikely to experience heat stress. Cavity-using species are a heterogeneous group such that empirical studies are required to identify those that may be vulnerable to heat stress if nest boxes are used to provide population support.

The Economic Value of Distributed Storage at Different Locations on an Electric Grid

The objective of this article is to analyze the system benefits of distributed storage at different locations on a grid that has a high penetration of renewable generation. The chosen type of distributed storage modeled is deferrable demand (e.g., thermal storage) because it is relatively inexpensive to install compared to batteries and could potentially form a large component of the peak system load. The advantage of owning deferrable demand is that the purchase of energy from the grid can be decoupled from the delivery of an energy service to customers. Consequently, these customers can reduce costs by shifting their purchases from expensive peak periods to off-peak periods when electricity prices are low. In addition, deferrable demand can provide ramping services to the grid to mitigate the uncertainty of renewable generation. The primary economic issue addressed in this paper is to determine how the storage capacity is allocated between shifting load and providing ramping services. The basic economic tradeoff is between the benefit from shifting more load from peak periods to less expensive periods, and reserving some storage capacity for ramping to reduce the amount of conventional reserve capacity purchased. Our approach uses a new form of stochastic, multi-period Security Constrained Optimal Power Flow (SCOPF) that minimizes the expected system costs for energy and ancillary services over a 24-hour horizon. For each hour, five different levels of wind generation may be realized and these are treated as different system states with known probabilities of occurring. This model is applied to a reduction of the grid in New York State and New England and simulates the hourly load on a hot summer day, treating potential wind generation at different sites as stochastic inputs. The results determine the expected amount and location of conventional generating capacity dispatched, the reserve capacity committed to maintain operating reliability, the charging/discharging of storage capacity, and the amount of potential wind generation spilled. The results show there are major differences in how the deferrable demand at two large load centers, Boston and New York City, is managed, and we provide an explanation for these differences.

Nighttime Cooling of an Urban Pond

One of the processes by which open water cools the air during hot summer days is by storing the heat and increasing its own temperature. This heat is then released at night. The aim of this paper is to analyze this cooling process by quantifying the magnitude of turbulent, latent and sensible, heat fluxes in comparison to radiative and ground fluxes. A detailed vertical temperature profile was measured in an urban pond (~70 cm deep with surface area of 3,627 m2) in Delft (NL) using Distributed Temperature Sensing for a period of one month. The results show that, from the total of 2.7 MJm−2 of heat released by the pond on an average summer night, 43% of the thermal energy is emitted as longwave radiation, 39% as latent energy, and only 11% as sensible heat. An additional 0.10–0.32 MJm−2 is transferred into the bottom of the lake. Temperature distribution and cooling of the water profile is influenced by weather conditions during the preceding day. This paper provides an insight into a behavioral pattern of an urban pond at night. The results can shed some light into the potential of urban bodies to increase the air temperature of their surroundings at night.

Nanofluid Based on Glucose‐Derived Carbon Dots Functionalized with [Bmim]Cl for the Next Generation of Smart Windows

AbstractThe design of new advanced materials and technologies is essential for the development of smart windows for the next generation of energy‐efficient buildings. Here, it is demonstrated that the functionalization of glucose‐derived carbon dots with 1‐butyl‐3‐methylimidazolium chloride results in a self‐standing, water‐soluble, viscous, reusable nanofluid with self‐improving conductivity, thermotropy around 30–40 °C, and ultraviolet blocking ability. Its synthesis is straightforward, clean, fast, and cheap. At 36 °C (hot summer day), a sun‐actuated thermotropic (TT) device incorporating a 95% w/w nanofluid aqueous solution exhibits a transmittance variation (ΔT) of 9% at 550/1000 nm, which is amplified to 47/31% via the surface plasmon resonance effect. An integrated self‐healing system enabling independent sun‐actuated TT and voltage‐actuated electrochromic (EC) operation is also produced. The low‐energy EC device offers bright hot and dark cold modes (ΔT = 68/64%), excellent cycling stability, unprecedented coloration efficiency values (−1.73 × 106/−1.67 × 106 cm2 C−1 (coloring) and +1.12 × 107/+1.08 × 107 cm2 C−1 (bleaching) at ±2.5 V), and impressive memory effect. The disruptive design and sustainable synthesis of the new nanofluid proposed here will foster the agile development of novel products with improved ecological footprint.

Investigation of naturally ventilated shavadoons component: Architectural underground pattern on ventilation

There is increasing concern about environmental pollution and the need for efficient energy sources. Thus, natural ventilation using renewable energy without the need for mechanical devices has gained great importance. A shavadoon is an example of a natural ventilation system used for cooling and heating in Dezful, a warm and semi-humid city in Iran. They are constructed at a depth of 5–12 m and utilize the high thermal capacity of the soil to have about 20 °C temperature below the ambient temperature during the hottest days of summer. In this study, the effect of shavadoons’ components like kat (a chamber of the main room, which is called the sahn), foot rest, and shabestan (a type of basement that connects the shavadoon to the main building) that can increase the volume of the stored air are investigated on natural ventilation and an ideal shape of the shavadoon is found. The results show that although adding the kats adjacent to the sahn (making the shavadoon’s cross-sectional area from simple form to a cruciform) can increase the storage cold air during the night, the backflow in stairway is increased and ventilation rate is decreased. In addition, foot rests were found to increase the inlet air flow and a four-fold increase in the foot rest volume, increased the air flow by 12.5%. Shabestan on the upper floor of the shavadoon enhances the inlet flow and improves the ventilation rate, although the shabestans are not used on hot summer days due to temperature fluctuations. So, shavadoons without Kats and with larger foot rests can be chosen as an optimal shape of Shavadoon.

The relationship of frequent tropical cyclone activities over the western North Pacific and hot summer days in central-eastern China

Tropical cyclones (TCs) formed over the western North Pacific (WNP) often make landfalls over East Asia and Southeast Asia, causing strong winds and torrential rain in the coastal countries. However, they also bring cool weather on hot summer days and mitigate drought impacts. The present study demonstrates that TC activities over the WNP can strongly modulate extreme summer weather events in eastern mainland China, i.e., frequent TC activities would indirectly lead to more hot days in central-eastern China along the lower and middle reaches of Yangtze River, besides compensating the decreasing of hot days induced by the direct impact of TCs. Such indirect impact is largely determined by the feedback effect of TCs on pressure system, especially on the western Pacific subtropical high, resulting in an abnormal anticyclonic circulation band that dominates a large area from central-eastern China to the Pacific Ocean to the east of Japan in the middle and lower troposphere.

Love by M. de la Peña

de la Peña, Matt. Love. Illustrated by Loren Long, G.P. Penguin Random House, 2018.&#x0D; Newbery Medal-winning author of Last Stop on Market Street Matt de la Peña and New York Times bestselling illustrator Loren Long have teamed up to paint a touching picture of where love lives in each of our lives. Perfect for the child in your life or the child in you, this book ignites a warm feeling deep down inside. Love shines through in all our senses. Through poetic verses we are reminded of what love looks like, what love sounds like, what love tastes like, what love smells like, and what love feels like, physically and emotionally. Who cannot relate to the simple innocence of laughing as you run through the sprinkler on a hot summer's day?&#x0D; One much-needed two-page spread even highlights the importance of self-love. The gorgeous illustrations are comprised of a compilation of monotype prints, acrylic paint, and pencil. They perfectly complement the words that they accompany, even telling their own hidden stories along the way. It is clear to understand how the pictures connect to the words, the two parts work together to invoke emotions in the reader. The vocabulary and structure, like how the word love is used in a variety of manners and how each page offers a glimpse into different individuals’ lives, may be challenging for younger children to read on their own but with the right facilitation any child can find connections to this beautiful picture book.&#x0D; Highly Recommended: 4 out of 4 starsReviewer: Bretton Bowd

Estimates of the impact of extreme heat events on cooling energy demand in Hong Kong

To better understand the relationship between energy consumption, and prevailing climatic condition, the present study uses Hong Kong’s observed air temperature records, end-use electricity consumption, and population datasets to: (a) investigate the spatial pattern of cooling energy requirement i.e. cooling degree days on a typical normal and extremely hot summer day using co-kriging geospatial mapping technique; (b) analyze the annual trend of cooling degree days in the city; and (c) quantify the impact of extreme heat events on the summer cooling energy requirements. Results revealed reasonable predictability of city-wide cooling degree days with the co-kriging method which uses two covariates i.e. “elevation of the weather station” and “building volume density within the 1000 m radius neighboring area”. Homogeneity and heterogeneity in cooling degree days’ distribution were found during the summer daytime and nighttime, respectively indicating the method’s ability to delineate the urban heat island effect with increased magnitude during extreme heat events. Quantitatively, the extreme heat events increased cooling degree days by 80–140% depending on the event type, a range consistent in recent years (2011–2015). Lastly, we provided the implications of our findings to building and urban design; and future energy planning.

Hot weather and residential hourly electricity demand in Italy

Concerns about climate change, pollution and energy security have prompted policies aiming at replacing fossil fuels (in heating and cooling, and transportation) with electricity, presumably generated from renewable sources. Climate change itself is expected to increase the demand for cooling in buildings, which is generally met with electricity-powered air conditioning. We use hourly electricity demand from a sample of Italian residences over a full year to examine how sensitive residential demand is to temperature. Our regression model includes a rich set of household-by-time fixed effects to control for dwelling characteristics and equipment, family composition, work and business schedules, demand for lighting, and seasonal habits other than temperature. These allows us to separate the effect of temperature from the demand for lighting and from other seasonal effects that may be correlated with temperature, but are not temperature. We find that demand stays unchanged within a relatively narrow range (and is thus relatively flat) up to temperatures of about 24.4 °C, and increases sharply with temperature thereafter. We find that temperature accounts for a very small share of daily electricity demand. Only on exceptionally hot summer days can temperature account for 12% of hourly electricity use.

Urban Trees and Their Impact on Local Ozone Concentration—A Microclimate Modeling Study

Climate sensitive urban planning involves the implementation of green infrastructure as one measure to mitigate excessive heat in urban areas. Depending on thermal conditions, certain trees tend to emit more biogenic volatile organic compounds, which act as precursors for ozone formation, thus hampering air quality. Combining a theoretical approach from a box model analysis and microscale modeling from the microclimate model ENVI-met, we analyze this relationship for a selected region in Germany and provide the link to air quality prediction and climate sensitive urban planning. A box model study was conducted, indicating higher ozone levels with higher isoprene concentration, especially in NO-saturated atmospheres. ENVI-met sensitivity studies showed that different urban layouts strongly determine local isoprene emissions of vegetation, with leaf temperature, rather than photosynthetic active radiation, being the dominant factor. The impact of isoprene emission on the ozone in complex urban environments was simulated for an urban area for a hot summer day with and without isoprene. A large isoprene-induced relative ozone increase was found over the whole model area. On selected hot spots we find a clear relationship between urban layout, proximity to NOx emitters, tree-species-dependent isoprene emission capacity, and increases in ozone concentration, rising up to 500% locally.

Evaluation of energy saving potential of an urban green space and its water bodies

Urban green space in modern cities displays a cooling effect on hot summer days, based on which its energy saving potential can be estimated. The current work studies the energy saving potential (ESP) of a Chinese traditional garden in Beijing on a hot summer day and provides the corresponding spatiotemporal distribution maps, with a specific focus on the effect of the garden's water body. For this purpose, numerical simulation using ENVI-met model is created and validated by field measurement. The maximum cooling effect in the garden is a change of 1.3 °C in air temperature reduction at 14:00. Of this change, over 0.8 °C is caused by the water body. The center of the water body has a significant cooling effect due to evaporation, absorption of short wave solar radiation and desirable ventilation conditions. Based on the cooling effect, the spatial distribution and time evolution of heat reduction and ESP for the garden and its water body is obtained. Time evolution of spatial 3D heat reduction and ESP of the entire garden shows that the best performance is achieved at around 14:00 within a vertical height of 0–20.5 m. The corresponding values are 1.0 × 108 J and 80.7 kWh. The best performance of the water body occurs at around 14:00–15:00 when the heat reduction and ESP are 5.4 × 107 J and 43.6 kWh. Finally, the distribution maps of spatiotemporal heat reduction and ESP caused by the water body and entire garden within a height of 0–20.5 m from 8:00 to 18:00 are constructed. The total heat reduction values caused by the water body and the entire garden were 4.7 × 108 and 8.6 × 108 J, and the corresponding ESP values were 379.3 and 694.1 kWh.

Energy, exergy and environmental impact analysis of concentrated PV/cooling system in Turkey

In this study, a Concentrated Photovoltaic Cooling System has been designed and a prototype has been produced. This system is intended to meet the need for cooling and electricity of the building where this system is applied in hot summer days. The produced prototype has been tested with/without using a concentrator. The obtained data was used to analyze the energy, exergy and environmental cost. During performance of experiments, using a concentrator did not affect the thermal energy gain and total thermal energy gain was calculated as approximately 30 W in the system. Besides, use of a concentrator increased the exergy efficiency. Using the concentrator increased the back side temperature of panels, thus electrical performance is lower than the systems without concentrator. The system allows to economize around 0.1 ¢ per hour due to reduced generation of CO2.

Quantifying the Evapotranspiration Rate and Its Cooling Effects of Urban Hedges Based on Three-Temperature Model and Infrared Remote Sensing

The evapotranspiration (ET) of urban hedges has been assumed to be an important component of the urban water budget and energy balance for years. However, because it is difficult to quantify the ET rate of urban hedges through conventional evapotranspiration methods, the ET rate, characteristics, and the cooling effects of urban hedges remain unclear. This study aims to measure the ET rate and quantify the cooling effects of urban hedges using the ‘three-temperature model + infrared remote sensing (3T + IR)’, a fetch-free and high-spatiotemporal-resolution method. An herb hedge and a shrub hedge were used as field experimental sites in Shenzhen, a subtropical megacity. After verification, the ‘3T + IR’ technique was proven to be a reasonable method for measuring the ET of urban hedges. The results are as follows. (1) The ET rate of urban hedges was very high. The daily average rates of the herb and shrub hedges were 0.38 mm·h−1 and 0.33 mm·h−1, respectively, on the hot summer day. (2) Urban hedges had a strong ability to reduce the air temperature. The two hedges could consume 68.44% and 60.81% of the net radiation through latent heat of ET on the summer day, while their cooling rates on air temperature were 1.29 °C min−1 m−2 and 1.13 °C min−1 m−2, respectively. (3) Hedges could also significantly cool the urban underlying surface. On the summer day, the surface temperatures of the two hedges were 19 °C lower than that of the asphalt pavement. (4) Urban hedges had markedly higher ET rates (0.19 mm·h−1 in the summer day) and cooling abilities (0.66 °C min−1 m−2 for air and 9.14 °C for underlying surface, respectively) than the lawn used for comparison. To the best of our knowledge, this is the first research to quantitatively measure the ET rate of urban hedges, and our findings provide new insight in understanding the process of ET in urban hedges. This work may also aid in understanding the ET of urban vegetation.

Short-term prediction of extremely hot days in summer due to climate change and ENSO and related attributable mortality

Summer days with extremely hot temperatures in Taiwan have been increasing for the past few decades, and this continuing trend is expected to worsen heat-related mortality. To mitigate the corresponding health impacts, in this study, we developed a statistical state-space model to predict the number of extremely hot days in June–September for the next year. Based on historical data from 1951 to 2017, we estimated the climate change trend after adjusting for the nonlinear lagged effect of the Niño 3.4 index. We then developed a predictive state-space model using these two primary factors and adjusting for residual autocorrelations. Validation results comparing the extremely hot days observed over 2015–2017 with predictions showed that 86% of the average prediction errors were within 4 days of the observations. To assess the health impacts, we applied the model to the projection of heat-attributable mortality (AM) in 2018 by adopting a comparative risk assessment (CRA) approach with the reference period of 2001–2010. The results showed that the Taipei metropolitan area in northern Taiwan is the most affected region with AM of 1501 deaths from all-causes, followed by Taichung in central Taiwan with 490 deaths. The prediction model and the CRA projection provide both a tool and guidance for public health administrators to address the imminent threat posed by climate change.

A Distinct Visual Pathway Mediates High-Intensity Light Adaptation of the Circadian Clock in Drosophila.

To provide organisms with a fitness advantage, circadian clocks have to react appropriately to changes in their environment. High-intensity (HI) light plays an essential role in the adaptation to hot summer days, which especially endanger insects of desiccation or prey visibility. Here, we show that solely increasing light intensity leads to an increased midday siesta in Drosophila behavior. Interestingly, this change is independent of the fly's circadian photoreceptor cryptochrome and is solely caused by a small visual organ, the Hofbauer-Buchner eyelets. Using receptor knock-downs, immunostaining, and recently developed calcium tools, we show that the eyelets activate key core clock neurons, namely the s-LNvs, at HI. This activation delays the decrease of PERIOD (PER) in the middle of the day and propagates to downstream target clock neurons that prolong the siesta. We show a new pathway for integrating light-intensity information into the clock network, suggesting new network properties and surprising parallels between Drosophila and the mammalian system.SIGNIFICANCE STATEMENT The ability of animals to adapt to their ever-changing environment plays an important role in their fitness. A key player in this adaptation is the circadian clock. For animals to predict the changes of day and night, they must constantly monitor, detect and incorporate changes in the environment. The appropriate incorporation and reaction to high-intensity (HI) light is of special importance for insects because they might suffer from desiccation during hot summer days. We show here that different photoreceptors have specialized functions to integrate low-intensity, medium-intensity, or HI light into the circadian system in Drosophila These results show surprising parallels to mammalian mechanisms, which also use different photoreceptor subtypes to respond to different light intensities.

Impact of Maximum Air Temperature on Ambulance Transports Owing to Heat Stroke During Spring and Summer in Tottori Prefecture, Japan: A Time-stratified Case-crossover Analysis

The frequency and intensity of hot weather have increased. In Japan, there have been many studies of the relationship between ambulance transports owing to heat stroke (ATHS) and high air temperature in the summer season. However, there have been very few reports focusing on ATHS in spring. Therefore, we investigated the effect of the maximum air temperature on ATHS not only in summer but also in spring, to help with development of effective measures to prevent heat stroke. We obtained daily ATHS and meteorological data from April to September in 2017 in Tottori Prefecture. We used a time-stratified case-crossover method for data analysis. A total 382 cases of ATHS were identified from April to September in 2017 in Tottori. The number of cases was highest in July, followed by August and May. Maximum air temperature was significantly linked to ATHS. The risk of ATHS was increased 1.13 times when maximum air temperature rose by 1°C. In summer, the risk on extremely hot days (maximum air temperature ≥ 35°C) increased by 5.55 times or more compared with that on days below 30 °C (< 30°C). The risk was approximately four times greater on hot days (≥ 30°C and < 35°C) than that on relatively cooler days (< 30°C) during the spring months of April through May. Maximum air temperature was significantly linked to ATHS. It is necessary to pay particular attention to heat stroke prevention not only on extremely hot days in summer but also on hot days in the spring.