Thermoregulatory, Perceptual, Cognitive, And Motor Responses During A Winter Firefighting Intervention In A Cold Environment

Firefighters are exposed to cold during winter interventions in Québec where the average temperature from December to March is approximately -13 to -5 °C with average minimum temperature of nearly -15 °C in the main urban areas. These environmental conditions can be detrimental to health and safety at work especially when firefighters are in defensive mode, which is common, to carry out different tasks outside the building that are generally less physically demanding. PURPOSE: To characterize the variation in 1) thermoregulatory, 2) perceptual, 3) cognitive and 4) motor responses resulting from cold exposure during a firefighting simulation. METHODS: Three counterbalanced visits exposed participants to three different ambient temperatures (A: 17 °C, B: 0 °C and C: -17 °C) at rest for 60 minutes following a firefighting simulation in a thermoneutral environment (22.6 ± 0.5 °C). The firefighting simulation consisted of a 25-minute effort period on a treadmill representative of the effort-rest cycles where specific firefighting tasks were performed. The variation in rectal and skin temperature, comfort perception, cognitive performance, manual dexterity, and grip strength between pre-firefighting and the end of the 60-minute cold exposure was measured. RESULTS: Eighteen (18) healthy adults (one female) (age: 25 ± 3 years) completed all visits. No significant difference was observed in rectal temperature variation (A: 0.26 ± 0.23; B: 0.21 ± 0.23; C: 0.09 ± 0.33 °C; interaction P = 0.11). Mean skin (A: -0.48 ± 1.39; B: -2.87 ± 0.98; C: -5.64 ± 1.53 °C) and finger temperature decrease (A: 0.28 ± 2.75; B: -13.53 ± 4.62; C: -24.14 ± 4.24 °C) was significantly greater in cold environments (interaction P < 0.01). Discomfort perception was also greater in cold environments (interaction P < 0.01). Time variation to complete cognitive tasks was not significantly different (all tasks P > 0.20). Variation in manual dexterity test completion time (A: -6.66 ± 15.78; B: -6.44 ± 17.05; C: 3.77 ± 16.22 s; interaction P = 0.30) and in grip strength (A: -4 ± 9; B: -2 ± 6; C: -3 ± 10 kg; interaction P = 0.68) was not significantly different. CONCLUSION: Although the effects of cold exposure on thermoregulatory and perceptual responses are considerable, they do no seem to have been sufficient to induce a decline in cognitive and motor performance.