scholarly journals Evolution of Heat Index (HI) and Physiological Equivalent Temperature (PET) Index at Mumbai and Pune Cities, India

MAUSAM ◽  
2021 ◽  
Vol 72 (4) ◽  
pp. 915-934
Author(s):  
MANASI DESAI ◽  
ASHISH NAVALE ◽  
AMIT G. DHORDE

In the present study, trends in heat stress during summer and monsoon season months were assessed for two cities, Pune and Mumbai, for the period of 47 years from 1969 to2015 with the application of empirically derived Heat Index (HI) and rational heat balance based Physiological Equivalent Temperature (PET) index. A stepwise multiple regression analysis was applied to determine contributing meteorological parameters responsible for changes in heat stress incidences. The study reveals a considerable increase in heat stress during the summer months over Mumbai compared to Pune city. Similarly, during the end months of monsoon season, thermal discomfort conditions aggravate over both the cities, with statistically significant rising trends. The actual identification and categorization of thermally discomfortable days during the study period in accordance with the Heat Index were moderate. They remained consistent in Pune during summer, however, in monsoon, heat stress incidences were meager. While at Mumbai days with 'High' and 'Very High,' heat stress have increased towards recent years. Categorization according to PET index depicted conspicuous presence of 'Strong' and 'Extreme heat stress' at Pune, while at Mumbai, 'Warm' and 'Hot' days portrayeda slight increase.  The assessment of meteorological parameters depicted that increased humidity and temperature were the main concern for the increase in heat stress over Mumbai. In contrast, mean radiant temperature, ambient air temperature with restricted wind speed leading to high sensible heat may be responsible for the significant increasing trend in PET. The study infers that both the cities are vulnerable to escalating heat stress and may have adverse implications on the health of city dwellers. 

2020 ◽  
pp. bjsports-2019-100632 ◽  
Author(s):  
Sofia Thorsson ◽  
David Rayner ◽  
Gunnar Palm ◽  
Fredrik Lindberg ◽  
Eric Carlström ◽  
...  

BackgroundThe Wet-Bulb Globe Temperature (WBGT) index is a common tool to screen for heat stress for sporting events. However, the index has a number of limitations. Rational indices, such as the physiological equivalent temperature (PET) and Universal Thermal Climate Index (UTCI), are potential alternatives.AimTo identify the thermal index that best predicts ambulance-required assistances and collapses during a city half marathon.MethodsEight years (2010–2017) of meteorological and ambulance transport data, including medical records, from Gothenburg’s half-marathon were used to analyse associations between WBGT, PET and UTCI and the rates of ambulance-required assistances and collapses. All associations were evaluated by Monte-Carlo simulations and leave-one-out-cross-validation.ResultsThe PET index showed the strongest correlation with both the rate of ambulance-required assistances (R2=0.72, p=0.008) and collapses (R2=0.71, p=0.008), followed by the UTCI (R2=0.64, p=0.017; R2=0.64, p=0.017) whereas the WBGT index showed substantially poorer correlations (R2=0.56, p=0.031; R2=0.56, p=0.033). PET stages of stress, match the rates of collapses better that the WBGT flag colour warning. Compared with the PET, the WBGT underestimates heat stress, especially at high radiant heat load. The rate of collapses increases with increasing heat stress; large increase from the day before the race seems to have an impact of the rate of collapses.ConclusionWe contend that the PET is a better predictor of collapses during a half marathon than the WBGT. We call for further investigation of PET as a screening tool alongside WBGT.


2019 ◽  
Vol 40 (05) ◽  
pp. 312-316 ◽  
Author(s):  
Eric Carlström ◽  
Mats Borjesson ◽  
Gunnar Palm ◽  
Amir Khorram-Manesh ◽  
Fredrik Lindberg ◽  
...  

AbstractThe aim was to analyze the influence of weather conditions on medical emergencies in a half-marathon, specifically by evaluating its relation to the number of non-finishers, ambulance-required assistances, and collapses in need of ambulance as well as looking at the location of such emergencies on the race course. Seven years of data from the world’s largest half marathon were used. Meteorological data were obtained from a nearby weather station, and the Physiological Equivalent Temperature (PET) index was used as a measure of general weather conditions. Of the 315,919 race starters, 104 runners out of the 140 ambulance-required assistances needed ambulance services due to collapses. Maximum air temperature and PET significantly co-variated with ambulance-required assistances, collapses, and non-finishers (R2=0.65–0.92; p=0.001–0.03). When air temperatures vary between 15–29°C, an increase of 1°C results in an increase of 2.5 (0.008/1000) ambulance-required assistances, 2.5 (0.008/1000) collapses (needing ambulance services), and 107 (0.34/1000) non-finishers. The results also indicate that when the daily maximum PET varies between 18–35°C, an increase of 1°C PET results in an increase of 1.8 collapses (0.006/1000) needing ambulance services and 66 non-finishers (0.21/1000).


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1498
Author(s):  
Mengbing Cao ◽  
Chao Zong ◽  
Yanrong Zhuang ◽  
Guanghui Teng ◽  
Shengnan Zhou ◽  
...  

Heat stress has an adverse effect on the production performance of sows, and causes a large economic loss every year. The thermal environment index is an important indicator for evaluating the level of heat stress in animals. Many thermal indices have been used to analyze the environment of the pig house, including temperature and humidity index (THI), effective temperature (ET), equivalent temperature index of sows (ETIS), and enthalpy (H), among others. Different heat indices have different characteristics, and it is necessary to analyze and compare the characteristics of heat indices to select a relatively suitable heat index for specific application. This article reviews the thermal environment indices used in the process of sow breeding, and compares various heat indices in four ways: (1) Holding the value of the thermal index constant and analyzing the equivalent temperature changes caused by the relative humidity. (2) Analyzing the variations of ET and ETIS caused by changes in air velocity. (3) Conducting a comparative analysis of a variety of isothermal lines fitted to the psychrometric chart. (4) Analyzing the distributions of various heat index values inside the sow barn and the correlation between various heat indices and sow heat dissipation with the use of computational fluid dynamics (CFD) technology. The results show that the ETIS performs better than other thermal indices in the analysis of sows’ thermal environment, followed by THI2, THI4, and THI7. Different pigs have different heat transfer characteristics and different adaptability to the environment. Therefore, based on the above results, the following suggestions have been given: The thermal index thresholds need to be divided based on the adaptability of pigs to the environment at different growth stages and the different climates in different regions. An appropriate threshold for a thermal index can provide a theoretical basis for the environmental control of the pig house.


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