Living in Western Australia induces some physiological adaptations of seasonal acclimatisation in the surgical burns team

Abstract

Seasonal acclimatization is known to result in adaptations that can improve heat tolerance. Staff who operate on burn injuries are exposed to thermally stressful conditions and seasonal acclimatization may improve their thermoeffector responses during surgery. Therefore, the aim of this study was to assess the physiological and perceptual responses of staff who operate on burn injuries during summer and winter, to determine whether they become acclimatized to the heated operating theater. Eight staff members had physiological and perceptual responses compared during burn surgeries conducted in thermoneutral (CON: 24.1 ± 1.2°C, 45 ± 7% relative humidity [RH]) and heated (HOT: 31.3 ± 1.6°C, 44 ± 7% RH) operating theaters, in summer and winter. Physiological parameters that were assessed included core temperature, heart rate, total sweat loss, sweat rate, and urinary specific gravity. Perceptual responses included ratings of thermal sensation and comfort. In summer, CON compared to winter CON, baseline (85 ± 15 bpm VS 94 ± 18 bpm), mean (84 ± 16 bpm VS 93 ± 18 bpm), and peak HR (94 ± 17 bpm VS 105 ± 19 bpm) were lower (p < 0.05), whereas core temperature was not different between seasons in either condition (p > 0.05). In HOT, ratings of discomfort were higher in summer (15 ± 3) than winter (13 ± 3; p > 0.05), but ratings of thermal sensation and sweat rate were similar between seasons (p > 0.05). The surgical team in burns in Western Australia can obtain some of the physiological adaptations that result from seasonal acclimatization, but not all. That is most likely due to a lower than required amount of outdoor heat exposure in summer, to induce all physiological and perceptual adaptations.

Keywords: Seasonal acclimatization; adaptations; burn surgery; core temperature; heart rate; heat stress; heat tolerance.

Figure 1.

Seasonal T_CORE responses in CON (a) and HOT (b) conditions.

Figure 2.

Seasonal HR responses in CON (a) and HOT (b) conditions.

Figure 3.

Total sweat loss in kg (a), total sweat loss as a percentage of body mass (b), and sweat rate (c) in CON and HOT surgeries, in summer and winter.

Figure 4.

“Pre” and “post” U_SG values in CON (a) and HOT (b) surgeries, in summer and winter.

Figure 5.

“Pre” and “post” perceptual responses in summer and winter; thermal sensation CON (a), thermal sensation HOT (b), thermal comfort CON (c), and thermal comfort HOT (d).