The heat is on: Observations and trends of heat stress metrics during Florida summers

2022 ◽  
Keyword(s):  
Heat Stress ◽  
Heat Waves ◽  
South Florida ◽  
Heat Index ◽  
Daily Maximum ◽  
Wet Bulb Globe Temperature ◽  
Key West ◽  
Outdoor Work ◽  
Temperature And Humidity ◽  
Globe Temperature

Abstract Extreme heat is annually the deadliest weather hazard in the U.S. and is strongly amplified by climate change. In Florida, summer heat waves have increased in frequency and duration, exacerbating negative human health impacts on a state with a substantial older population and industries (e.g., agriculture) that require frequent outdoor work. However, the combined impacts of temperature and humidity (heat stress) have not been previously investigated. For eight Florida cities, this study constructs summer climatologies and trend analyses (1950–2020) of two heat stress metrics: heat index (HI) and wet bulb globe temperature (WBGT). While both incorporate temperature and humidity, WBGT also includes wind and solar radiation, and is a more comprehensive measure of heat stress on the human body. With minor exceptions, results show increases in average summer daily maximum, mean, and minimum HI and WBGT throughout Florida. Daily minimum HI and WBGT exhibit statistically significant increases at all eight stations, emphasizing a hazardous rise in nighttime heat stress. Corresponding to other recent studies, HI and WBGT increases are largest in coastal subtropical locations in Central and South Florida (i.e., Daytona Beach, Tampa, Miami, Key West), but exhibit no conclusive relationship with urbanization changes. Finally, danger (103–124°F) HI and high (> 88°F) WBGT summer days exhibit significant frequency increases across the state. Especially at coastal locations in the Florida Peninsula and Keys, danger HI and high WBGT days now account for > 20% of total summer days, emphasizing a substantial escalation in heat stress, particularly since 2000.

scholarly journals An Evaluation of Portable Wet Bulb Globe Temperature Monitor Accuracy

2017 ◽  
Vol 52 (12) ◽  
pp. 1161-1167 ◽  
Author(s):  
Earl Cooper ◽  
Andrew Grundstein ◽  
Adam Rosen ◽  
Jessica Miles ◽  
Jupil Ko ◽  
...  
Keyword(s):  
Physical Activity ◽  
Heat Stress ◽  
Sports Medicine ◽  
Pearson Correlation ◽  
Heat Stroke ◽  
Heat Index ◽  
Mean Bias Error ◽  
Bias Error ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature

Context:  Wet bulb globe temperature (WBGT) is the gold standard for assessing environmental heat stress during physical activity. Many manufacturers of commercially available instruments fail to report WBGT accuracy. Objective:  To determine the accuracy of several commercially available WBGT monitors compared with a standardized reference device. Design:  Observational study. Setting:  Field test. Patients or Other Participants:  Six commercially available WBGT devices. Main Outcome Measure(s):  Data were recorded for 3 sessions (1 in the morning and 2 in the afternoon) at 2-minute intervals for at least 2 hours. Mean absolute error (MAE), root mean square error (RMSE), mean bias error (MBE), and the Pearson correlation coefficient (r) were calculated to determine instrument performance compared with the reference unit. Results:  The QUESTemp° 34 (MAE = 0.24°C, RMSE = 0.44°C, MBE = –0.64%) and Extech HT30 Heat Stress Wet Bulb Globe Temperature Meter (Extech; MAE = 0.61°C, RMSE = 0.79°C, MBE = 0.44%) demonstrated the least error in relation to the reference standard, whereas the General WBGT8778 Heat Index Checker (General; MAE = 1.18°C, RMSE = 1.34°C, MBE = 4.25%) performed the poorest. The QUESTemp° 34 and Kestrel 4400 Heat Stress Tracker units provided conservative measurements that slightly overestimated the WBGT provided by the reference unit. Finally, instruments using the psychrometric wet bulb temperature (General, REED Heat Index WBGT Meter, and WBGT-103 Heat Stroke Checker) tended to underestimate the WBGT, and the resulting values more frequently fell into WBGT-based activity categories with fewer restrictions as defined by the American College of Sports Medicine. Conclusions:  The QUESTemp° 34, followed by the Extech, had the smallest error compared with the reference unit. Moreover, the QUESTemp° 34, Extech, and Kestrel units appeared to offer conservative yet accurate assessments of the WBGT, potentially minimizing the risk of allowing physical activity to continue in stressful heat environments. Instruments using the psychrometric wet bulb temperature tended to underestimate WBGT under low wind-speed conditions. Accurate WBGT interpretations are important to enable clinicians to guide activities in hot and humid weather conditions.

scholarly journals Assessment of Heat Stress Exposure among Construction Workers in the Hot Desert Climate of Saudi Arabia

2019 ◽  
Vol 63 (5) ◽  
pp. 505-520 ◽  
Author(s):  
Mohammed Al-Bouwarthan ◽  
Margaret M Quinn ◽  
David Kriebel ◽  
David H Wegman
Keyword(s):  
Saudi Arabia ◽  
Heat Stress ◽  
Heat Exposure ◽  
Construction Workers ◽  
Heat Index ◽  
Stress Exposure ◽  
Construction Sites ◽  
Excessive Heat ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature

Abstract Objectives Excessive heat exposure poses significant risks to workers in hot climates. This study assessed the intensity and duration of heat stress exposure among workers performing residential construction in southeastern Saudi Arabia (SA) during the summer, June–September 2016. Objectives were to: identify work factors related to heat stress exposure; measure environmental heat exposure at the construction sites; assess the heat stress risk among workers using the wet bulb globe temperature (WBGT) index; and determine if temperature-humidity indices can be appropriate alternatives to WBGT for managing heat stress risk at the construction sites. Methods Worksite walkthrough surveys and environmental monitoring were performed, indoors and outdoors, at 10 construction sites in Al-Ahsa Province. A heat stress exposure assessment was conducted according to the American Conference of Governmental Industrial Hygienists (ACGIH®) guidelines, which uses the WBGT index. WBGT measurements from two instruments were compared. Alternative heat stress indices were compared to the WBGT: the heat index (HI) and humidex (HD) index. Results Construction workers were exposed to excessive heat stress, indoors and outdoors over a large part of the work day. Complying with a midday outdoor work ban (12–3 p.m.) was not effective in reducing heat stress risk. The highest intensity of exposure was outdoors from 9 a.m. to 12 p.m.; a period identified with the highest hourly mean WBGT values (31–33°C) and the least allowable working time according to ACGIH® guidelines. Comparison of the alternative indices showed that the HI is more reliable than the HD as a surrogate for the WBGT index in the climate studied. Conclusion The extreme heat exposure represents a serious risk. The severity of heat stress and its impact are projected to increase due to climate change, emphasizing the need for immediate improvement of the current required protective measures and the development of occupational heat stress exposure guidelines in SA.

scholarly journals Obravnava vročinskih valov in primer toplotne obremenitve delavcev v kmetijstvu v času vročinskih valov 2017

2018 ◽  
Vol 111 (3) ◽  
pp. 647
Author(s):  
Tjaša POGAČAR ◽  
Lučka KAJFEŽ BOGATAJ ◽  
Zalika ČREPINŠEK
Keyword(s):  
Heat Stress ◽  
Heat Waves ◽  
Labour Productivity ◽  
Temperature Threshold ◽  
Temperature Index ◽  
Wet Bulb Globe Temperature ◽  
Air Temperatures ◽  
Globe Temperature ◽  
High Level ◽  
Continental Climate

Workers in agriculture are regularly exposed to heat stress during summer, which can affect reduced labour productivity and income losses. Air temperatures in Slovenia have been rising in recent decades, and climate change projections show that this trend will continue along with an increase in the number of days with heat stress risk. Changes in the number of heat waves in central and south-western Slovenia for the period 1961–2017 were analysed as well as the risk of the heat stress for workers during heat waves in the year 2017. The heat wave occurs if the temperature threshold for the average daily temperature is reached or exceeded on at least three consecutive days, with the threshold for the mild continental climate (Ljubljana) 24 °C and the mild Submediterranean climate (Bilje) 25 °C. The WBGT (Wet Bulb Globe Temperature) index, assessing the risk of heat stress, was calculated from relative humidity and air temperatures. At both locations, the number of days in heat waves increased as well as their intensity, average daily air temperatures were significantly higher than in the first half of the considered period. The time span, in which the heat waves occur, also extended, as until 1990 they did not appear in early June and late August, as in recent years. The calculated values of the WBGT show that for most days in the heat waves in 2017 in Ljubljana and Bilje, the WBGT 23 °C threshold was exceeded practically all day, which shows a high level of heat stress risk for physically intense work. In the case of exceeded WBGT reference values, employers or farmers themselves should take actions to reduce the risk of heat stress.

scholarly journals Heat Warnings in Switzerland: Reassessing the Choice of the Current Heat Stress Index

2019 ◽  
Vol 16 (15) ◽  
pp. 2684 ◽  
Author(s):  
Annkatrin Burgstall ◽  
Ana Casanueva ◽  
Sven Kotlarski ◽  
Cornelia Schwierz
Keyword(s):  
Heat Stress ◽  
Added Value ◽  
Heat Index ◽  
Stress Index ◽  
Stress Indices ◽  
Wet Bulb Globe Temperature ◽  
Human Stress ◽  
Weather Stations ◽  
Globe Temperature ◽  
Heat Stress Index

High temperatures lead to heat-related human stress and an increased mortality risk. To quantify heat discomfort and the relevant dangers, heat stress indices combine different meteorological variables such as temperature, relative humidity, radiation and wind speed. In this paper, a set of widely-used heat stress indices is analyzed and compared to the heat index currently used to issue official heat warnings in Switzerland, considering 28 Swiss weather stations for the years 1981–2017. We investigate how well warnings based on the heat index match warning days and warning periods that are calculated from alternative heat stress indices. The latter might allow for more flexibility in terms of specific warning demands and impact-based warnings. It is shown that the percentage of alternative warnings that match the official warnings varies among indices. Considering the heat index as reference, the simplified wet bulb globe temperature performs well and has some further advantages such as no lower bound and allowing for the calculation of climatological values. Yet, other indices (e.g., with higher dependencies on humidity) can have some added value, too. Thus, regardless of the performance in terms of matches, the optimal index to use strongly depends on the purpose of the warning.

scholarly journals New and Old Indices for Evaluating Heat Stress in an Indoor Environment: Some Considerations. Comment on Kownacki, L.; Gao, C.; Kuklane, K.; Wierzbicka, A. Heat Stress in Indoor Environments of Scandinavian Urban Areas: A Literature Review. Int. J. Environ. Res. Public Health 2019, 16 (4), 560. doi:10.3390/ijerph16040560

2019 ◽  
Vol 16 (8) ◽  
pp. 1444 ◽  
Author(s):  
Francesco Chirico ◽  
Nicola Magnavita
Keyword(s):  
Heat Stress ◽  
Urban Areas ◽  
Heat Index ◽  
Indoor Environments ◽  
Wet Bulb Globe Temperature ◽  
Comfort Index ◽  
Predicted Heat Strain ◽  
Thermal Work ◽  
Globe Temperature ◽  
Heat Indices

In their review, Kownacki et al. showed some practical and easy to use workplace heat indices that are useful for indoor environments, namely the “Wet Bulb Globe Temperature” (WBGT), the “Predicted Heat Strain” (PHS) model, the “Thermal Work Limit” (TWL), the “Equivalent Temperature” (ET) and the thermal comfort index “PMV/PPD”. In this letter, the authors explain why the modified PMV/PPD method together with the indices combining temperature with humidity, such as the “Humidex Index” and the “Heat Index”, could be a more feasible and useful tool for evaluating potential thermal stress in indoor environments for both the occupational and general population.

scholarly journals Assessing the Climatological Relationship between Heatstroke Risk and Heat Stress Indices in 47 Prefectures in Japan

GeoHazards ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 321-331
Author(s):  
Yuki Iwamoto ◽  
Yukitaka Ohashi
Keyword(s):  
Heat Stress ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Climate Index ◽  
Daily Maximum ◽  
Stress Indices ◽  
Wet Bulb Globe Temperature ◽  
Thermal Climate ◽  
Globe Temperature ◽  
Northern Japan

This study provides a decade-long link between summer heatstroke incidence and certain heat stress indices in 47 prefectures of Japan. The results for each prefecture were determined from the age-adjusted heatstroke incidence rate (TRadj) with heatstroke patients transported by ambulance, as well as from the daily maximum temperature (TEMPmax), maximum wet-bulb globe temperature (WBGTmax), and maximum universal thermal climate index (UTCImax) recorded from July to September of 2010–2019. The UTCImax relatively increased the vulnerability in many prefectures of northern Japan more distinctly than the other indices. In the following analysis, the ratio of the TRadj of the hottest to coolest months using the UTCImax was defined as the heatstroke risk of the hottest to coolest (HRHC). Overall, the HRHC varied approximately from 20 to 40 in many prefectures in the past decade. In contrast, for the same analysis performed in each month, HRHC ratios in July and August fell within 2–4 in many prefectures, whereas in September, the average and maximum HRHC ratios for all prefectures were 7.0 and 32.4, respectively. This difference can be related to the large difference in UTCImax between the maximum and minimum for a decade.

EFFECTS OF INONIZING RADIATION CAUSED HEAT STRESS ON THE HUMAN BODY FOR STANDARD ISO 7243

2013 ◽  
pp. 47-57
Author(s):  
Van Trong Le ◽  
Thi Tuyet Mai Nguyen ◽  
Thi Xuan Duyen Nguyen ◽  
Ba Luan Nguyen ◽  
Tuyen Pham ◽  
...  
Keyword(s):  
Heat Stress ◽  
Risk Assessments ◽  
Management Systems ◽  
Temperature Index ◽  
Wet Bulb Globe Temperature ◽  
Simple Index ◽  
Simple Tool ◽  
Results Management ◽  
Globe Temperature ◽  
Hot Environments

Objectives: Presents heat stress Standard ISO 7243, which is based upon the wet bulb globe temperature index (WBGT), and considers its suitability for use worldwide. Materials and Methods: The WBGT index are considered and how it is used in ISO 7243 and across the world as a simple index for monitoring and assessing hot environments. Results: Management systems, involving risk assessments, that take account of context and culture, are required to ensure successful use of the standard and global applicability. For use outdoors, a WBGT equation that includes solar absorptivity is recommended. A ‘clothed WBGT’ is proposed to account for the effects of clothing. Conclusion: ISO 7243 is a simple tool to assess the heat stress and may be applicated worldwide.

scholarly journals The Extent of Heat on Health and Sustainable Farming in Ghana –Bawku East

2014 ◽  
Vol 3 (3) ◽  
pp. 56 ◽  
Author(s):  
Frimpong Kwasi ◽  
Jacque Oosthuizen ◽  
Eddie Van Etten
Keyword(s):  
Developing Countries ◽  
Health Effects ◽  
Rural Areas ◽  
High Heat ◽  
Northern Ghana ◽  
Tropical Regions ◽  
Wet Bulb Globe Temperature ◽  
Time Period ◽  
Outdoor Work ◽  
Globe Temperature

<p>Little is known about the health effects of heat in outdoor work and appropriate work and rest schedules for farmers working in developing countries. As temperatures continue to increase in tropical regions, such as Northern Ghana, it is necessary to evaluate how farmers experience and respond to high heat exposures. In this study, WBGT (Wet Bulb Globe Temperature) estimates and the ISO work / rest standards were applied to a cohort of farmers in the rural areas of Bawku East, Northern Ghana, to assess how farmers respond to high heat and how much they rest to protect their health, as well as the level of heat on their productivity. WBGT data was recorded over a period of 6 months among vegetable, cereals, and legume farmers. The ISO proposed and actual rest regimes observed by farmers in the same time period were evaluated. In the dry season the dry bulb temperature rose as high as 45 ºC, while during the humid months of March and April WBGT rose to levels as high as 34 ºC. Farmers worked for nine hours a day during these hot periods with insufficient rest, which has adverse consequences on their health and productivity.</p>

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