Although the severity of a burn injury is often associated with the percentage of total body surface area burned (%TBSA), the thermoregulatory consequences of a given %TBSA injury do not account for the interactive effects of body morphology and metabolic heat production (Hprod).
Using a simulated burn injury model to mimic the detrimental effect of a 40% TBSA injury on whole-body evaporative heat dissipation, core temperature response to exercise in physiologically uncompensable conditions between morphologically disparate groups were examined at (i) an absolute Hprod
(W), and (ii) a mass-specific Hprod
Healthy, young, nonburned individuals of small (SM, n
= 11) or large (LG, n
= 11) body size cycled for 60 min at 500 W or 5.3 W·kg−1
in 39°C and 20% relative humidity conditions. A 40% burn injury was simulated by affixing a highly absorbent, vapor-impermeable material across the torso (20% TBSA), arms (10% TBSA), and legs (10% TBSA) to impede evaporative heat loss in those regions.
Although the elevation in core temperature was greater in SM compared with LG at an Hprod
of 500 W (SM, 1.69°C ± 0.26°C; LG, 1.05°C ± 0.26°C; P
< 0.01), elevations in core temperature were not different at an Hprod
of 5.3 W·kg−1
between groups (SM, 0.99°C ± 0.32°C; LG, 1.05°C ± 0.26°C; P
These data suggest that among individuals with a 40% TBSA burn injury, a smaller body size leads to exacerbated elevations in core temperature during physical activities eliciting the same absolute Hprod
(non–weight-bearing tasks) but not activities eliciting the same mass-specific Hprod