Burn Injury Does Not Exacerbate Heat Strain during Exercise while Wearing Body Armor

Med Sci Sports Exerc. 2020 Oct;52(10):2235-2241. doi: 10.1249/MSS.0000000000002375.

Abstract

Introduction: Although evaporative heat loss capacity is reduced in burn-injured individuals with extensive skin grafts, the thermoregulatory strain due to a prior burn injury during exercise-heat stress may be negligible if the burn is located underneath protective clothing with low vapor permeability.

Purpose: This study aimed to test the hypothesis that heat strain during exercise in a hot-dry environment while wearing protective clothing would be similar with and without a simulated torso burn injury.

Methods: Ten healthy individuals (8 men/2 women) underwent three trials wearing: uniform (combat uniform, tactical vest, and replica torso armor plates), uniform with a 20% total body surface area simulated torso burn (uniform + burn), or shorts (and sports bra) only (control). Exercise consisted of treadmill walking (5.3 km·h; 3.7% ± 0.9% grade) for 60 min at a target heat production of 6.0 W·kg in 40.0°C ± 0.1°C and 20.0% ± 0.6% relative humidity conditions. Measurements included rectal temperature, heart rate, ratings of perceived exertion (RPE), and thermal sensation.

Results: No differences in rectal temperature (P ≥ 0.85), heart rate (P ≥ 0.99), thermal sensation (P ≥ 0.73), or RPE (P ≥ 0.13) occurred between uniform + burn and uniform trials. In the control trial, however, core temperature, heart rate, thermal sensation, and RPE were lower compared with the uniform and uniform + burn trials (P ≤ 0.04 for all).

Conclusions: A 20% total body surface area simulated torso burn injury does not further exacerbate heat strain when wearing a combat uniform. These findings suggest that the physiological strain associated with torso burn injuries is not different from noninjured individuals when wearing protective clothing during an acute exercise-heat stress.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Body Temperature
  • Body Temperature Regulation*
  • Burns / complications*
  • Exercise / physiology*
  • Female
  • Heart Rate
  • Heat Stress Disorders / complications*
  • Heat Stress Disorders / physiopathology*
  • Hot Temperature*
  • Humans
  • Male
  • Military Personnel
  • Perception / physiology
  • Physical Exertion / physiology
  • Protective Clothing*
  • Rectum / physiology
  • Thermosensing
  • Young Adult