Effects Of Extreme Temperatures Research Articles

Impact of Adverse Environmental Conditions on Rotorcraft Operational Performance and Pollutant Emissions

It is anticipated that the contribution of rotorcraft activities to the environmental impact of civil aviation will increase in the future. Due to their versatility and robustness, helicopters are often operated in harsh environments with extreme ambient conditions. These severe conditions not only affect the performance of the engine but also affect the aerodynamics of the rotorcraft. This impact is reflected in the fuel burn and pollutants emitted by the rotorcraft during a mission. The aim of this paper is to introduce an exhaustive methodology to quantify the influence adverse environment conditions have in the mission fuel consumption and the associated emissions of nitrogen oxides (NOx). An emergency medical service (EMS) and a search and rescue (SAR) mission are used as case studies to simulate the effects of extreme temperatures, high altitude, and compressor degradation on a representative twin-engine medium (TEM) weight helicopter, the Sikorsky UH-60A Black Hawk. A simulation tool for helicopter mission performance analysis developed and validated at Cranfield University was employed. This software comprises different modules that enable the analysis of helicopter flight dynamics, powerplant performance, and exhaust emissions over a user-defined flight path profile. For the validation of the models implemented, extensive comparisons with experimental data are presented throughout for rotorcraft and engine performance as well as NOx emissions. Reductions as high as 12% and 40% in mission fuel and NOx emissions, respectively, were observed for the “high and cold” scenario simulated at the SAR role relative to the same mission trajectory under standard conditions.

The impact of heat waves and cold spells on respiratory emergency department visits in Beijing, China

The objectives of this article were (i) to find the association between extreme temperatures and respiratory emergency department (ED) visits and (ii) to explore the added effects of heat waves and cold spells on respiratory ED visits in Beijing from 2009 to 2012. A quasi-Poisson generalised linear model combined with a distributed lag non-linear model was performed to quantify this association. The results indicated that (i) ambient temperature related to respiratory ED visits exhibited a U-shaped association. The minimum-morbidity temperature was 21.5°C. (ii) the peak relative risk (RR) of cold spells on respiratory ED visits was observed in relatively mild cold spells with a threshold below the 3rd percentile for 4days (RR=1.885, 95% CI: 1.300–2.734), and there was a reduction in risk during extremely chilly cold spells (RR=1.811, 95% CI: 1.229–2.667). However, the risk of heat waves increased with the thresholds, and the greatest risk was found for extremely hot heat waves (RR=1.932, 95% CI: 1.461–2.554). (iii) the added effect of heat waves was small, and we observed that the added heat wave effect only introduced additional risk in females (RR=1.166, 95% CI: 1.007–1.349). No added effect of cold spells was identified. In conclusion, the main effects of heat waves and cold spells on respiratory ED visits showed different change trends. In addition, the added effects of extreme temperatures on respiratory ED visits were small and negligible.

Ground vibration propagation measurements in extreme conditions

Ground vibration propagation measurements are often required during the environmental impact assessment process for transit projects per Federal Transit Administration (FTA) guidance. Cross-Spectrum Acoustics (CSA) conducted these measurements in extremely hot (100 + degrees Fahrenheit) and extremely cold (sub-zero degrees Fahrenheit) environments in 2016. This presentation will provide an overview of conducting such procedures in extreme climates and lessons learned from CSA staff. Topics to be discussed will include the effects of extreme temperatures on equipment, staff, and the collected data.

Effects of extreme temperatures on the growth and photosynthesis of invasive Bidens alba and its native congener B. biternata

Temperatures are expected to fluctuate widely under climate change but little is known about how extreme temperatures might affect the physiology and performance of invasive compared to native plant species. In this study, we evaluated the effects of high (40/35°C) and low (10/5°C) temperature regimes on the growth and photosynthesis of the invasive Asteraceae species Bidens alba and its native congener B. biternata using a growth chamber experiment. Results showed that invasive B. alba had significantly greater total biomass and relative growth rate, accompanied by higher net photosynthetic rate (Pn), than native B. biternata at both low and high temperature extremes. The reduction in Pn for B. alba was mainly caused by stomatal limitations, but for B. biternata it was caused by non‐stomatal factors, indicating that greater damage to physiological processes may occur in native B. biternata under both low and high temperature stress. Higher cyclic electron flow around photosystem I in invasive B. alba than in native B. biternata under extreme temperatures might alleviate the negative effect of temperature extremes to photosynthetic and thus promote its photosynthetic efficiency. To conclude, the invasive B. alba has both greater cold and heat tolerance than its native congener B. biternata, suggesting that the invader may outperform native species under future extreme temperature conditions.

Effects of extreme temperatures on cardiovascular emergency hospitalizations in a Mediterranean region: a self-controlled case series study

BackgroundCold spells and heatwaves increase mortality. However little is known about the effect of heatwaves or cold spells on cardiovascular morbidity. This study aims to assess the effect of cold spells and heatwaves on cardiovascular diseases in a Mediterranean region (Catalonia, Southern Europe).MethodsWe conducted a population-based retrospective study. Data were obtained from the System for the Development of Research in Primary Care and from the Catalan Meteorological Service. The outcome was first emergency hospitalizations due to coronary heart disease, stroke, or heart failure. Exposures were: cold spells; cold spells and 3 or 7 subsequent days; and heatwaves. Incidence rate ratios (IRR) and 95% confidence intervals were calculated using the self-controlled case series method. We accounted for age, time trends, and air pollutants; results were shown by age groups, gender or cardiovascular event type.ResultsThere were 22,611 cardiovascular hospitalizations in winter and 17,017 in summer between 2006 and 2013. The overall incidence of cardiovascular hospitalizations significantly increased during cold spells (IRR = 1.120; CI 95%: 1.10–1.30) and the effect was even stronger in the 7 days subsequent to the cold spell (IRR = 1.29; CI 95%: 1.22–1.36). Conversely, cardiovascular hospitalizations did not increase during heatwaves, neither in the overall nor in the stratified analysis.ConclusionsCold spells but not heatwaves, increased the incidence of emergency cardiovascular hospitalizations in Catalonia. The effect of cold spells was greater when including the 7 subsequent days. Such knowledge might be useful to develop strategies to reduce the impact of extreme temperature episodes on human health.

Extreme temperature and out-of-hospital cardiac arrest in Japan: A nationwide, retrospective, observational study

BackgroundAlthough several studies have estimated the effect of extreme temperatures on out-of-hospital cardiac arrest (OHCA) in a single city or region, few have investigated variations in this association on a national level in Japan. MethodsDaily data on OHCAs and weather variations were obtained from the 47 prefectures of Japan between 2005 and 2014. A time-series Poisson regression model with a distributed lag non-linear model was used to estimate the prefecture-specific effects. A multivariate meta-analysis was applied to pooled estimates on a national level. ResultsA total of 659,752 OHCA cases of presumed-cardiac origin met the inclusion criteria. The minimum morbidity percentile (MMP) was identified as the 84th percentile for temperature, ranging from 20.8°C in Hokkaido to 28.8°C in Okinawa. The overall pooled relative risk versus the MMP was 2.10 (95% CI: 1.84, 2.40) at extremely low temperatures (1st percentile) and 1.06 (95% CI: 1.01, 1.12) at extremely high temperatures (99th percentile). The effects of extremely high temperatures were acute and disappeared after a few days, while those of extremely low temperatures were also acute, but persisted for several days. The multivariate Cochran's Q test indicated no heterogeneity between prefectures (p=0.699; I2=1.0%). ConclusionsExtreme temperatures are associated with an increased risk of OHCA. Timely prevention strategies might reduce the risk of OHCA during extreme temperatures. Several days prevention should be also implemented for extremely low temperatures.

Pivotal effect of early‐winter temperatures and snowfall on population growth of alpineParnassius smintheusbutterflies

AbstractGeographic range shifts in species’ distributions, due to climate change, imply altered dynamics at both their northern and southern range limits, or at upper and lower elevational limits. There is therefore a need to identify specific weather or climate variable(s), and life stages or cohorts on which they act, and how these affect population growth. Identifying such variables permits prediction of population increase or decline under a changing climate, and shifts in a species’ geographic range. For relatively well studied groups, such as butterflies, geographic range shifts are well documented, but weather variables and mechanisms causing those shifts are not well known. The Holarctic butterfly genusParnassius(Papilionidae) inhabits northern and alpine environments subject to variable and extreme weather. As such,Parnassiusspecies are vulnerable not only to long‐term changes in average conditions but especially to short‐term extreme weather events. We use population growth estimates for the alpine butterfly,Parnassius smintheus, from 21 populations in the Rocky Mountains of Canada over a 20‐yr interval combined with techniques of machine learning (randomForests) and parametric modeling to identify the important weather variables determining population growth. We do this to determine the seasons and life stages ofP. smintheusmost affected by climate change. Extreme minimum and maximum temperatures in November, in combination with November snowfall, affect annual population growth most, more so than do mean temperatures in November, and more so than weather at any other time of year. Populations decline both in years with low extreme minimum temperatures in November and especially in years with high extreme maximum temperatures in November, indicating that overwintering eggs are particularly vulnerable to early‐winter weather. Snowfall ameliorates the negative effects of extreme temperatures, particularly for extreme warm events. Results provide insight into biological mechanisms by which overwintering eggs might be affected by early winter weather. Short‐term extreme weather in November, acting on a single pivotal life stage (egg) is a far better predictor of population change of alpineP. smintheusbutterflies than is the general index of climate, the Pacific Decadal Oscillation.

The effect of rainfall and temperature on road traffic injuries in Rome, Italy

Introduction: Previous studies have shown that rainfall has an impact on road traffic injuries, however there is less evidence on the effects of extreme temperatures. The aim of the study is to ass...

Effect of extreme temperatures on battery charging and performance of electric vehicles

Abstract Extreme temperatures pose several limitations to electric vehicle (EV) performance and charging. To investigate these effects, we combine a hybrid artificial neural network-empirical Li-ion battery model with a lumped capacitance EV thermal model to study how temperature will affect the performance of an EV fleet. We find that at −10 °C, the self-weighted mean battery charging power (SWMCP) decreases by 15% compared to standard 20 °C temperature. Active battery thermal management (BTM) during parking can improve SWMCP for individual vehicles, especially if vehicles are charged both at home and at workplace; the median SWMCP is increased by over 30%. Efficiency (km/kWh) of the vehicle fleet is maximized when ambient temperature is close to 20 °C. At low (−10 °C) and high (+40 °C) ambient temperatures, cabin preconditioning and BTM during parking can improve the median efficiency by 8% and 9%, respectively. At −10 °C, preconditioning and BTM during parking can also improve the fleet SOC by 3–6%-units, but this also introduces a “base” load of around 140 W per vehicle. Finally, we observe that the utility of the fleet can be increased by 5%-units by adding 3.6 kW chargers to workplaces, but further improved charging infrastructure would bring little additional benefit.

A systematic review of epinephrine degradation with exposure to excessive heat or cold

BackgroundEpinephrine is a lifesaving drug in the treatment of anaphylaxis and cardiac resuscitation. Current US storage recommendations are for controlled room temperature (20°C–25°C), with excursions permitted from 15°C to 30°C. Maintaining epinephrine within this required range is challenging, particularly for patients carrying autoinjectors and during storage in emergency vehicles. ObjectiveTo study epinephrine degradation with extreme temperature exposure for epinephrine concentrations used in anaphylaxis and cardiac resuscitation. MethodsWe searched the literature for all studies of epinephrine in sealed syringes, vials, or ampules in concentrations between 1:1,000 and 1:10,000, that measured epinephrine in samples exposed to temperatures above and/or below the recommended storage temperature compared with control samples. ResultsNine studies were included. Heat exposure resulted in epinephrine degradation but only with prolonged exposure. Constant heat resulted in more degradation. None of the studies that evaluated epinephrine exposure to extreme cold found significant degradation. None of the studies evaluating the effects of real-world temperature fluctuations detected significant degradation. Only 2 small studies (1 evaluating heat and 1 freezing) involved autoinjectors, and all 40 devices tested fired correctly. ConclusionTemperature excursions in real-world conditions may be less detrimental than previously suggested. Freezing and limited heat excursions did not result in epinephrine degradation. Refrigeration of epinephrine appears to reduce degradation. However, the effect of extreme temperatures, particularly freezing, on autoinjectors is not sufficiently well established. More research in needed at clinically relevant high temperatures, with limited exposure to heat, and involving autoinjector devices.

Mortality attributable to extreme temperatures in Spain: A comparative analysis by city

BackgroundThe Low Temperature Days (LTD) have attracted far less attention than that of High Temperature Days (HTD), though its impact on mortality is at least comparable. This lower degree of attention may perhaps be due to the fact that its influence on mortality is less pronounced and longer-term, and that there are other concomitant infectious winters factors. In a climate-change scenario, the studies undertaken to date report differing results. The aim of this study was to analyse mortality attributable to both thermal extremes in Spain's 52 provinces across the period 2000–2009, and estimate the related economic cost to show the benefit or “profitability” of implementing prevention plans against LTD. MethodsPrevious studies enabled us: to obtain the maximum daily temperature above which HTD occurred and the minimum daily temperature below which LTD occurred in the 52 provincial capitals analysed across the same study period; and to calculate the relative and attributable risks (%) associated with daily mortality in each capital. These measures of association were then used to make different calculations to obtain the daily mean mortality attributable to both thermal extremes. To this end, we obtained a summary of the number of degrees whereby the temperature exceeded (excess °C) or fell short (deficit °C) of the threshold temperature for each capital, and calculated the respective number of extreme temperatures days. The economic estimates rated the prevention plans as being 68% effective. ResultsOver the period considered, the number of HTD (4373) was higher than the number of LTD (3006) for Spain as a whole. Notwithstanding this, in every provincial capital the mean daily mortality attributable to heat was lower (3deaths/day) than that attributable to cold (3.48deaths/day). In terms of the economic impact of the activation of prevention plans against LTD, these could be assumed to avoid 2.37 deaths on each LTD, which translated as a saving of €0.29M. Similarly, in the case of heat, 2.04 deaths could be assumed to be avoided each day on which the prevention plan against HTD was activated, amounting to a saving of €0.25M. While the economic cost of cold-related mortality across the ten-year period 2000–2009 was €871.7M, that attributable to heat could be put at €1093.2M. ConclusionThe effect of extreme temperatures on daily mortality was similar across the study period for Spain overall. The lower number of days with LTD meant, however, that daily cold-related mortality was higher than daily heat-related mortality, thereby making prevention plans against LTD more “profitable” prevention plans against HTD in terms of avoidable mortality.

Daily mortality changes in Taiwan in the 1970s: An examination of the relationship between temperature and mortality

Growing evidence indicates that world temperatures have increased in recent history, and that this trend is likely to continue in the future. The rise in global temperatures has been accompanied by an increase in extreme weather events, which often have devastating environmental, economic, demographic, and social effects. As concern about the impact of climate change has grown in recent years, there has been a considerable increase in the number of studies published on the effects of extreme temperatures. However, detailed, systematic, and historical investigations into the relationship between temperature and mortality relationship are still difficult to find. This study fills some of these gaps. By examining the impact of extreme temperatures on mortality in Taiwan in the 1970s, our aim is to answer the following questions: (1) Is a lower or a higher temperature recorded in winter or summer related to higher daily mortality? (2) Is mortality higher in particular years with extreme temperatures than it is in the corresponding periods of other years with normal temperatures? (3) Finally, if more extreme temperatures are indeed associated with higher mortality, what kinds of people tend to face higher mortality risks? This study shows that variations in daily mortality were related to changes in temperature in Taiwan over the study period. Cold temperatures in the winter, hot temperatures in the summer, and unusually cold or hot temperatures were all associated with higher mortality. In comparison with other times of the year, the proportions of people who died at old or very young ages were relatively high during cold periods. The proportions of deaths caused by cardiovascular diseases were also relatively high, and these deaths contributed to the high mortality levels in winter time. Meanwhile, during the hot periods relatively high proportions of children and young people died of injuries or poisoning, and relatively high proportions of people died of respiratory diseases; both of these causes of death were closely related to mortality increases in the summer. In comparison with recent decades, however, these patterns were more observable in the 1970s, when the public health and the socioeconomic development levels in Taiwan were not as advanced as they are today.

Comparison of the effects of extreme temperatures on daily mortality in Madrid (Spain), by age group: The need for a cold wave prevention plan

A number of studies have shown that there is a time trend towards a reduction in the effects of heat on mortality. In the case of cold, however, there is practically no research of this type and so there is no clearly defined time trend of the impact of cold on mortality. Furthermore, no other specific studies have yet analysed the time trend of the impact of both thermal extremes by age group.We analysed data on daily mortality due to natural causes (ICD-10: A00-R99) in the city of Madrid across the period 2001–2009 and calculated the impact of extreme temperatures on mortality using Poisson regression models for specific age groups. The groups of age selected coinciding with the pre-existing age-groups analyzed in previous papers. For heat waves the groups of age used were: <10 years, 10–17 years, 18–44 years, 45–64 years, 65–74 years and over-75 years. For cold waves the groups of age used were: <1 year; 1–5 years, 6–17 years, 18–44 years, 45–64 years, 65–74 years and over-75 years. <1, 1–17, 18–44, 45–66, 65–74 and over-75 years. We controlled for confounding variables, such as air pollution, noise, influenza, pollen, pressure and relative humidity, trend of the series, as well as seasonalities and autoregressive components of the series. The results of these models were compared to those obtained for the same city during the period 1986–1997 and published in different studies.Our results show a lightly reduction in the effects of heat, especially in the over-45-year age group. In the case of cold, the behaviour pattern was the opposite, with an increase in its effect. Heat adaptation and socio-economic and public-health prevention and action measures may be behind this amelioration in the effects of heat, whereas the absence of such actions in respect of low temperatures may account for the increase in the effects of cold on mortality. From a public health point of view, the implementation of cold wave prevention plans covering all age groups is thus called for.

Local Calibration of a Permanent Deformation Model for Asphalt Pavements Using Long-term Field Data

A permanent deformation model of asphalt pavements based on shear properties was locally calibrated and validated using long-term field data in Jiangsu of China. The detailed information on the climate, traffic, distresses, pavement structures, and materials for 24 pavement sections from 4 main lines in highway network was widely investigated. The required material parameters in the prediction model including dynamic modulus |E*|, cohesion, and friction angle were directly measured on 9 types of asphalt mixtures in laboratory. The hourly pavement temperature field in each analysis period was predicted using a transient finite element method model based on heat transfer theory. The sub-season concept based on normal frequency distribution function was employed to consider the effects of extreme temperatures. A conversion equation of axle load based on rutting equivalent principle was developed for traffic characterization. Traffic wander and load frequency distribution were also carefully considered in the calibration process. After statistical optimization using a three-step procedure the optimum combination of calibration factors were obtained by minimizing the sum of squared errors between the predicted and measured permanent deformation. It is found from the validation research that the locally calibrated model can provide reasonable predictions for various asphalt pavements and satisfy the accuracy requirement in engineering practice.

Individual-level and community-level effect modifiers of the temperature–mortality relationship in 66 Chinese communities

ObjectivesTo examine the modification of temperature-mortality association by factors at the individual and community levels.Design and methodsThis study investigated this issue using a national database comprising daily data of 66...

Effect of extreme temperatures at different stages during grain filling on rice seed weight and germination and its regulations

A series of studies were carried out in chamber room to investigate the injury mechanism under extreme temperature and at different grain filling stages with foliar application of plant growth regulators (Abscisic acid-ABA and salicylic acid-SA) on the rice cultivar Huanghuazhan. Grain filling rate and grain weight were measured as yield components, while seed germination rate, germination index and seed vigour index were measured as seed quality indices. Chlorophyll fluorescence parameters and active oxygen resistance activity were also analyzed. The results showed that the rate of grain filling and grain weight were significantly reduced under the extreme temperature conditions and at higher concentrations of the plant growth regulators. Superoxide dismutase (SOD) activity increased and decreased among treatments, while malondialdehyde (MDA) content was significantly high. Maximal photochemical efficiency of PS II (Fv/Fm) and the potential photochemical efficiency of PS II (Fv/Fo) also decreased under high temperature stress, whilst it increased and decreased under low temperature stress among treatments.

CALIDAD Y RENDIMIENTO DE JITOMATE VARIANDO EL CALCIO EN UN SISTEMA NFT EN INVERNADERO

The current research was conducted in a greenhouse of 20 m2 area located at the University of Chapingo, Mexico, in hydroponic system (NFT) with recirculating nutrient solution, three treatments were applied (100, 150 and 200 ppm) of calcium concentration to study effects on fruit quality and yield of tomato (Lycopersicum esculentum Mill.). The experiment was conducted from September 30, 2010 to February 4, 2011 and random samples of fruits were collected for three consecutive weeks, where each week were harvested fruits of the first to the third cluster of each plant. Treatment two showed the highest yield and it was obtained in the second cluster with 57.1 %, in treatment one on the third week was 37.5 % and yield treatment three during the second and third week was 38.6 % with respect to the total. The fruits quality was good because tomatoes showed good acidity and salt content as recommended. However the sugar content was low and statistically different compared with previous reported studies. The average yield was low and different in all cases due to the effect of extreme temperatures outside the range of 10-25 °C and these results cannot be asigned to the concentration of calcium because there were not significant differences among the treatments.

Extremely cold and hot temperatures increase the risk of diabetes mortality in metropolitan areas of two Chinese cities

BackgroundNumerous studies have reported the association between ambient temperature and mortality. However, few studies have focused on the effects of extreme temperatures on diabetes mortality, particularly in China. The objective of the present study was to assess the effects of extremely cold and hot temperatures on diabetes mortality in urban areas of Harbin and Chongqing in China to provide scientific evidence for public health policy implementation to respond to challenges in diabetes mortality because of extreme temperature events. MethodsA double threshold B-spline distributed lag non-linear model (DLNM) was used to investigate the effects of extremely cold and hot temperatures on diabetes mortality from lag 0 to 30 days, after controlling for potential confounders including air pollutants. The unit risk, which is the elevated cumulative risk of diabetes mortality caused by each 1°C change in extremely cold and hot temperatures during certain lag days, was estimated for extreme cold and heat using simple regression analysis. ResultsSignificant associations between both extreme hot and cold temperatures and diabetes mortality were observed in Harbin and Chongqing for different lag lengths. In Harbin, the extreme cold effects on diabetes mortality were delayed by three days and lasted for six days (lag 3–8), with the highest risk (RR 95% CI: 1.223,1.054–1.418 for −23°C) at lag 5. The hot effects were delayed one day and lasted for three days (lag 1–3), with the peak RR (1.343: 1.080–1.670 for 37°C) at lag 2. In Chongqing, the cold effects on diabetes mortality were delayed by seven days and lasted for four days (lag 7–10), with the highest risk (1.201: 1.006–1.434 for 4°C) at lag 7. The hot effects peaked (1.811: 1.083–3.027 for 41°C) at lag 0 and lasted for 2 days (lag 0–1). The unit risk for cold and hot effects was 12.9% (95% CI: 2.5–33.7%) and 16.5% (95% CI: 3.8–39.1%) in Harbin and 12.5% (95% CI: −4.7 to 47.5%) and 19.7% (95% CI: 3.9–48.5%) in Chongqing, respectively. ConclusionsThe results indicate that both extremely cold and hot temperatures increase diabetes mortality in different manners in Harbin and Chongqing. Diabetes education programs should include information on either managing or combating the effects of extreme hot and cold weather.

Obesity and the natural environment across US counties.

We estimated the association between obesity and features of the natural environment. We asked whether the association is mediated by diet or by physical activity. Using county-level data from the contiguous United States, we regressed adult obesity prevalence on 9 measures of the natural environment. Our regression model accounted for spatial correlation, and controlled for county demographics and the built environment. We included physical activity and diet (proxied by food purchases) as potential mediators. Obesity was more prevalent in counties that are hot in July or cold in January. To a lesser degree, obesity was more prevalent in counties that are dark in January or rainy (but not snowy) year-round. Other aspects of the natural environment-including wind, trees, waterfront, and hills and mountains-had little or no association with obesity. Nearly all of the association between obesity and the natural environment was mediated by physical activity; none was mediated by diet. Hot summers and cold winters appear to promote obesity by discouraging physical activity. Attempts to encourage physical activity should compensate for the effects of extreme temperatures.

Effects of extreme temperature on seedling establishment of nonnative invasive plants

Climate change and plant invasion are two of the most important ecological issues facing the world today. Extreme events are likely to play an important role in plant invasion. For example, tolerance to temperature stress is critical for plant germination and survival of seedlings. Nonnative invasive species tend to differ from co-occurring native species in several traits. Increased mean temperatures are known to enhance the risk of plant invasions, but few experimental studies have linked plant invasion to both increasing mean temperature and extreme (low and high) temperatures. Ten plant species from Asteraceae (six nonnative invasive and four native species) were chosen and six temperatures (extremely low, average winter, average annual, average summer, high and extremely high) were used to test the effects of extreme temperatures on plant invasion in southern China. The results showed that nonnative invasive plant species (IS) germinated more readily and the seedlings grew better than those of native plant species (NS) at high temperatures, suggesting that global warming may facilitate invasion. Extreme temperatures decreased the seed germination rate and seedling growth of both IS and NS, although NS were more tolerant of extremely low temperatures (5/0 °C). IS, in turn, were more tolerant of extremely high temperatures (40/35 °C). Extreme high temperatures may increase the risk of plant invasion because IS seedlings are better able to become established, whereas low temperatures may hinder invasion. In addition, the species-specific differences in plant origin (IS and NS) and temperature tolerance were correlated with other climatic factors and should be considered in managing invasive species in a changing world.