The Potential Efficacy of Continuous Plantar Foot Cooling During Relatively Mild Simulated Occupational Heat Stress - A Pilot Study

Details

• Journal Article:
  European Journal of Applied Physiology
• Personal Author:
  Keeler, Jason M. ; Walker, Charlie ; Regester, Amanda ; Heikkinen, Molly E. ; Johnson, Blair D. ; Ju, Y. Sungtaek ; Jin, Lihua ; Schlader, Zachary J.
• Description:
  Purpose: To identify the effect size regarding glabrous skin foot cooling on core temperature, cognitive performance, and physical work capacity (PWC) during mild simulated occupational heat stress. Methods: A pilot sample of twelve healthy adults (5 women) completed experimental visits in a 38.7 +/- 0.7 degrees C, and 46 +/- 9% relative humidity environment that consisted of 60-minutes of steady-state upper body ergometry exercise followed by a 60-minute PWC test involving upper body ergometry while maintaining a rating of perceived exertion of 13 ("somewhat hard"). In one trial, participants stood with bare feet on cooled plates (17.7 +/- 0.5 degrees C,) and in the other they were on noncooled plates (36.5 +/- 0.1 degrees C,), with the order assigned in a block randomized manner. Results: Core temperature increased during steady-state exercise (from 37.5 +/- 0.3 to 37.6 +/- 0.3 degrees C,, p < 0.003) and the PWC test (from 37.6 +/- 0.3 to 37.9 +/- 0.3 degrees C, p < 0.001), but there was no difference between conditions (mean difference 0.03+/-0.18 degrees C,, p = 0.592, dz=0.112). During the PWC test, there was no difference between conditions for mean power output (p = 0.213, dz=0.184), with the final power outputs of 28 +/- 9 W and 30 +/- 9 W for control and cooling conditions, respectively. There were no condition effects for cognitive performance on any measure (p = 0.207, dz=0.405). However, foot cooling (+ 15 +/- 9 bpm) reduced increases of heart rate during the PWC test compared to control (+ 21 +/- 11 bpm, p = 0.013, dz=0.425). Conclusion: Glabrous skin foot cooling has a relatively small effect on core temperature and PWC, but moderate effects on cognitive performance and heart rate during short duration (approx. 3 h) mild heat stress.
• Subjects:
  • Heat Stress Disorders
  • Occupational Health
  • Safety
• Keywords:
  • Heat stress; Cognitive function; Body temperature; Work capacity; Humidity; Heart rate;
  • Author Keywords: Heat stress; Foot cooling; Core temperature; Work capacity
• Source:
  Eur J Appl Physiol 2025 Nov; :Epub ahead of print
• ISSN:
  1439-6319
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Indiana ; North Carolina ; California ; Chicago Region OSHA ; Atlanta Region OSHA ; San Francisco Region OSHA
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  15 pdf pages
• NIOSHTIC Number:
  nn:20071243
• Contact Point Address:
  Zachary J. Schlader, Department of Kinesiology, Indiana University School of Public Health, Bloomington, IN, USA
• Email:
  zschlade@iu.edu
• Federal Fiscal Year:
  2026
• Performing Organization:
  Indiana University, Bloomington
• Peer Reviewed:
  True
• Start Date:
  20190901
• End Date:
  20240831
• Download URL:
  https://stacks.cdc.gov/view/cdc/258721/cdc_258721_DS1.pdf
• File Type:
  [PDF - 4.56 MB]
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8dced7cdf71345a873a3fc00d619d1fd1023e53810962de4836df6f4687eba12772767445983bf3802139780b0fed63d030132c0a9c50f2b785cc516ecf83584