Living in Western Australia induces some physiological and perceptual adaptations of seasonal acclimatization in the surgical burns team

ABSTRACTSeasonal 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 comfort 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 and perceptual 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 acclimatizationburn surgeryadaptationsheat toleranceheat stresscore temperatureheart rateDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThe authors thank the burns team at Fiona Stanley Hospital for their participation and the Fiona Wood Foundation for their support with the research.ABBREVIATIONSHR=Heart rateIPAQ=International physical activity questionnaireMET=Metabolic equivalentOT=Operating theatrePPE=Personal protective equipmentRH=Relative humidityTBSA=Total body surface areaTC=Thermal comfortTcore=Core temperatureTS=Thermal sensationUSG=Urinary specific gravityWVP=Water vapour pressureDisclosure statementThe authors report there are no competing interests to declare.Data availabilityThe data that supports the findings of this study are available from the corresponding author [ZP] upon reasonable request.Fig 1. Seasonal TCORE responses in CON (A) and HOT (B) conditions.Display full size# Moderate effect size between seasons in specified condition (g = 0.47).Individual and mean data shown Fig 2. Seasonal HR responses in CON (A) and HOT (B) conditions.Display full size** Main effect (season); significant difference between seasons in specified condition and variable (p < .01); # Moderate effect size between seasons in specified condition (g = 0.48-0.55).Individual and mean data shown Fig 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.Display full size* Main effect (season); significant difference between seasons in specified condition and variable (p < .05); ** Main effect (season) significant difference between seasons in specified condition and variable (p < .01); # Moderate effect size between seasons in specified condition (g = 0.46-0.92).Individual and mean data shown.Fig 4. ‘Pre’ and ‘Post’ USG values in CON (A) and HOT (B) surgeries, in summer and winter.Display full size* Main effect (season); significant difference between seasons in specified condition (p < .05); *** main effect (time); significant difference between scores pre- and post-surgery in specified condition and (p < .001). # moderate effect size between seasons at specified time point and in specified condition (g = 0.57).Individual and mean data shownFig 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).Display full size*Main effect (season); significant difference between scores in summer and winter in specified condition (p < .05); ** Main effect (time); significant difference between scores pre- and post-surgery in specified condition (p < .01); *** main effect (time); significant difference between scores pre- and post-surgery in specified condition and (p < .001). # moderate to large effect size between seasons at specified time point and in specified condition (g = 0.52 – 0.73).Individual and mean data shown.Additional informationFundingThis work was supported by the Fiona Wood Foundation