Description:
<jats:title>ABSTRACT</jats:title>
<jats:p>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 (<jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub>).</jats:p>
<jats:sec>
<jats:title>Purpose</jats:title>
<jats:p>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 <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> (W), and (ii) a mass-specific <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> (W·kg<jats:sup>−1</jats:sup>).</jats:p>
</jats:sec>
<jats:sec>
<jats:title>Methods</jats:title>
<jats:p>Healthy, young, nonburned individuals of small (SM, <jats:italic toggle="yes">n</jats:italic> = 11) or large (LG, <jats:italic toggle="yes">n</jats:italic> = 11) body size cycled for 60 min at 500 W or 5.3 W·kg<jats:sup>−1</jats:sup> of <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> 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.</jats:p>
</jats:sec>
<jats:sec>
<jats:title>Results</jats:title>
<jats:p>Although the elevation in core temperature was greater in SM compared with LG at an <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> of 500 W (SM, 1.69°C ± 0.26°C; LG, 1.05°C ± 0.26°C; <jats:italic toggle="yes">P</jats:italic> < 0.01), elevations in core temperature were not different at an <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> of 5.3 W·kg<jats:sup>−1</jats:sup> between groups (SM, 0.99°C ± 0.32°C; LG, 1.05°C ± 0.26°C; <jats:italic toggle="yes">P</jats:italic> = 0.66).</jats:p>
</jats:sec>
<jats:sec>
<jats:title>Conclusions</jats:title>
<jats: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 <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> (non–weight-bearing tasks) but not activities eliciting the same mass-specific <jats:italic toggle="yes">H</jats:italic>
<jats:sub>prod</jats:sub> (weight-bearing tasks).</jats:p>
</jats:sec>