Medicine and Health Sciences Commons^™

Assessment Of Iso Heart Rate Method To Estimate Metabolic Rate, Karl Williams

USF Tampa Graduate Theses and Dissertations

Thermal equilibrium is primarily maintained by the body’s ability to dissipate internal heat generated during muscle contraction. A number of methods have been used to quantify this thermal burden such as charts and observation of workplace activities and behavior, however these have varying levels of validity. ISO 8996 defines a more accurate method of metabolic rate estimation that uses heart rate and maximal work capacity (MWC); however this requires the use of laboratory settings and equipment that are rarely available in the field. Equations such as the ACSM metabolic equation for the total energy expenditure of walking, hereafter referred to …

Evaluation Of Two Methods To Estimate Wet Bulb Globe Temperature From Heat Index, Stephi Pofanl

USF Tampa Graduate Theses and Dissertations

The Wet bulb globe temperature (WBGT) is a common method to evaluate environmental factors that contribute to occupational heat stress. The Heat Index (HI) is readily available as an alternative to exposure methods. They both assess the most important contributors that are air temperature and humidity. WBGT also includes radiant heat and air motion. To account for radiant heat and/or air motion, some investigators have suggested adjustments to HI. The purpose of this study is to explore two methods to estimate the usefulness of WBGT from HI.

WBGT data were collected in a variety of locations that included direct sun …

Does Time-Weighted Averaging For Wbgt And Metabolic Rate Work For Work-Recovery Cycles?, John W. Flach

USF Tampa Graduate Theses and Dissertations

Heat stress affects thousands of works annually by causing heat-related illnesses. Wet bulb globe temperature (WBGT) is a widely accepted metric to assess the environmental contributions to heat stress. WBGT-based occupational exposure limits (OELs) include the ACGIH TLVs and the NIOSH RELs. The OEL threshold is adjusted downward with increasing metabolic rate. Further, there is an OEL for acclimatized and non-acclimatized workers. An often-recommended intervention found within a heat stress management program is work-recovery cycles to manage exposure. To prescribe work-recovery cycles, the common practice is to use time-weighted averaging (TWA) for the WBGT and the metabolic rate. The purpose …

Analyzing Indoor And Outdoor Heat Index Measurements In Kitchens, Allison Welch

USF Tampa Graduate Theses and Dissertations

Occupationally induced heat-related illnesses (HRI) can play a huge part in the lives of employees working within outdoor kitchens. According to the National Institute for Occupational Safety and Health [NIOSH] (2016), “exposure to heat can result in injuries, disease, reduced productivity and death”. When working in outdoor environments, it is important to limit exposure time of direct sun or heat as well as to stay properly hydrated. One way to ensure limited occupational heat exposure is by measuring the Heat Index of the worker's environmental conditions.

The purpose of this study is to determine whether there was a difference between …

Can The Usa National Weather Service Heat Index Substitute For Wet Bulb Globe Temperature For Heat Stress Exposure Assessment?, Ivory Iheanacho

USF Tampa Graduate Theses and Dissertations

Heat stress occurs when the body cannot adequately cool itself due to the combined contributions of metabolic heat, environmental factors and clothing. Heat stress found in the workplace puts employees at risk of developing heat-related illnesses, disorders and could be fatal. The wet bulb globe temperature (WBGT) index is the current method used to assess environmental contributions to heat stress in an occupational setting. The purpose of this thesis was to explore whether the National Weather Service's Heat Index (HI) could substitute for the WBGT Index during occupational heat stress exposure assessment. The possibility of using the HI for heat …

Performance Assessment Of Predicted Heat Strain In High Heat Stress, Ronald Eugene Long

USF Tampa Graduate Theses and Dissertations

Heat stress is a common physical agent associated with many occupations. The most commonly used method of assessing heat stress exposure is an empirical method using the Wet Bulb Globe Temperature Index but his method is limited in its ability to parse out individual contributors to the heat stress. The International Organization for Standardization (ISO) published a rational model called Predicted Heat Strain (PHS) in 2004, and rational methods have the advantage of separating out the individual pathways for heat exchange. The objective of this research was a performance assessment of the current PHS model. This experimental design consisted of …

Heat Stress Evaluation Of Protective Clothing Ensembles, Amanda Lee Pease

USF Tampa Graduate Theses and Dissertations

Clothing directly affects the level of heat stress exposure. Useful measures to express the thermal characteristics are WBGT (wet bulb globe temperature) clothing adjustment factor (CAF) or apparent total evaporative resistance (R_e,T,_a). The CAF is assigned through laboratory wear trials following a heat stress protocol in which the air temperature and humidity are progressively increased until the participant clearly loses the ability to maintain thermal equilibrium. The critical condition is the point of thermal transition and from these conditions both the CAF and Re,T,a are computed. The first objective of this study is to compare the …