Apparent Total Evaporative Resistance Values from Human Trials over a Range of Heat Stress Levels

Details

• Personal Author:
  Dooris MD
• Description:
  Failure to maintain thermal equilibrium can cause uncontrollable increases in body core temperature beyond critical upper limits. In selecting clothing, consideration must be given to the heat transfer properties of clothing that may restrict the cooling capacity of the human body under heat stress conditions, most importantly, apparent total evaporative resistance (Re,T,a). This study calculated and compared Re,T,a for five clothing ensembles under varying heat stress conditions, including three relative humidity (RH) levels and three stages of heat stress to determine if Re,T,a values varied or remained the same with changes in heat stress conditions. A four-way mixed model analysis of variance demonstrated significant differences for estimated Re,T,a values among ensembles, RH levels, heat stress stages, and interactions among ensembles and RH levels and ensembles and heat stress stages (p < 0.0001). No significant interaction among RH levels and heat stress stages was found (p = 0.67). A Tukey's Honestly Significant Difference multiple comparison test was used to identify where significant differences occurred (p < 0.05). The results of the study indicated that Re,T,a values do change with RH levels and stages of heat stress and that the theoretical framework for explaining heat-exchange in hot environments is not yet well-established. Also confirmed was the dominance of the convection pathway over the diffusion pathway in hot environments. [Description provided by NIOSH]
• Subjects:
  Heat Stress Disorders Hot Temperature Occupational Health Personal Protective Equipment Safety Temperature
• Keywords:
  Author Keywords: Protective Clothing Clothing Convective Transport Evaporative Cooling Heat Exchange Heat Exposure Heat Stress PPE Temperature Effects Water Vapor Diffusion
• ISBN:
  9781124565569
• Publisher:
  ProQuest LLC.
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Thesis
• Place as Subject:
  Florida ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20056665
• Citation:
  Ann Arbor, MI: ProQuest LLC., 2011 Mar; :1490779
• Federal Fiscal Year:
  2011
• Performing Organization:
  University of South Florida, Tampa, Florida
• Peer Reviewed:
  False
• Start Date:
  20000930
• Source Full Name:
  Apparent total evaporative resistance values from human trials over a range of heat stress levels
• End Date:
  20040929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:415bd4ece8b05ba2472133495d23d2a6c219d0ec33fbb3581a348fd288bc0240e7d537792ba4738c8510646898ab3e20468294bc7e92cd2bb99f5448c53ad1ab
• Download URL:
  https://stacks.cdc.gov/view/cdc/214221/cdc_214221_DS1.pdf
• File Type:
  [PDF - 382.77 KB ]