Physiological and perceptual responses of wearing a dryrobe for rewarming after passive cold-water immersion in men

Objectives: To investigate the physiological and perceptual responses to wearing a dryrobe for rewarming after passive cold-water immersion (CWI).

Methods: 15 unhabituated healthy Caucasian men (age: 28.9 (5.4) years) attended the laboratory on three occasions and performed passive CWI (14°C) for 30 min followed by 15 min of rewarming wearing either a dryrobe, towel or foil blanket while positioned in front of fans replicating a 10 mph wind. Physiological (deep body temperature, skin temperature and heart rate) and perceptual (thermal sensation and thermal comfort) variables were measured.

Results: At 15 min post-immersion, deep body temperature was higher in the dryrobe condition (mean: 37.09 (SD: 0.49)°C) compared with the foil blanket (36.98 (0.64)°C) and towel (36.99 (0.49)°C) (p<0.001). On average across the 15 min post-immersion period, the dryrobe increased skin temperature to the greatest degree (18.9 (1.0)°C, +2.4°C), compared with the foil blanket (18.1 (1.2)°C, +1.8°C, p=0.034) and the towel (16.6 (1.2)°C, +1.3°C, p<0.001). Average heart rate across the 15 min post-immersion period was lower when wearing the dryrobe (dryrobe: 74 (10) b.min^-1, foil blanket: 78 (6) b.min^-1 and towel: 82 (14) b.min^-1 (p=0.015). Thermal sensation and thermal comfort were higher at all post-immersion time points in the dryrobe compared with the foil blanket and towel.

Conclusions: During the rewarming period following CWI, physiological and perceptual responses are improved when wearing clothing that combines an insulative layer with a vapour barrier, such as the dryrobe compared with a towel or foil blanket. This might have future implications for safety recommendations during rewarming.