title: Nongrafted Skin Area Best Predicts Exercise Core Temperature Responses in Burned Humans.
abstract: Grafted skin impairs heat dissipation, but it is unknown to what extent this affects body temperature during exercise in the heat.
  
  
  OBJECTIVE
  We examined core body temperature responses during exercise in the heat in a group of individuals with a large range of grafts covering their body surface area (BSA; 0%-75%).
  
  
  METHODS
  Forty-three individuals (19 females) were stratified into groups based on BSA grafted: control (0% grafted, n = 9), 17%-40% (n = 19), and >40% (n = 15). Subjects exercised at a fixed rate of metabolic heat production (339 ± 70 W; 4.3 ± 0.8 W·kg) in an environmental chamber set at 40°C, 30% relative humidity for 90 min or until exhaustion (n = 8). Whole-body sweat rate and core temperatures were measured.
  
  
  RESULTS
  Whole-body sweat rates were similar between the groups (control: 14.7 ± 3.4 mL·min, 17%-40%: 12.6 ± 4.0 mL·min; and >40%: 11.7 ± 4.4 mL·min; P > 0.05), but the increase in core temperature at the end of exercise in the >40% BSA grafted group (1.6°C ± 0.5°C) was greater than the 17%-40% (1.2°C ± 0.3°C) and control (0.9°C ± 0.2°C) groups (P < 0.05). Absolute BSA of nongrafted skin (expressed in square meters) was the strongest independent predictor of the core temperature increase (r = 0.41). When regrouping all subjects, individuals with the lowest BSA of nongrafted skin (<1.0 m) had greater increases in core temperature (1.6°C ± 0.5°C) than those with more than 1.5 m nongrafted skin (1.0°C ± 0.3°C; P < 0.05).
  
  
  CONCLUSIONS
  These data imply that individuals with grafted skin have greater increases in core temperature when exercising in the heat and that the magnitude of this increase is best explained by the amount of nongrafted skin available for heat dissipation.
authors.affiliation: 1Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas, TX; and Department of Internal Medicine University of Texas Southwestern Medical Center, Dallas, TX; 2Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR; 3Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY; 4Department of Biology, University of Colorado - Colorado Springs, Colorado Springs, CO; 5Center for Global Health Research, Umeå University, Umeå, SWEDEN; 6Department of Kinesiology, Texas Woman's University, Denton, TX; 7Department of Physical Medicine and Rehabilitation, University of Texas Southwestern Medical Center, Dallas, TX.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Ganio
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Schlader
authors.forename: James
authors.initials: J
authors.lastname: Pearson
authors.forename: Rebekah A I
authors.initials: RA
authors.lastname: Lucas
authors.forename: Daniel
authors.initials: D
authors.lastname: Gagnon
authors.forename: Eric
authors.initials: E
authors.lastname: Rivas
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Kowalske
authors.forename: Craig G
authors.initials: CG
authors.lastname: Crandall
mesh_terms: D000328:Adult; D001830:Body Surface Area; D001833:Body Temperature Regulation / Q000502:physiology*; D002056:Burns / Q000601:surgery*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D016038:Skin Transplantation; D013546:Sweating / Q000502:physiology; D055815:Young Adult