Duration limits for exposure for the whole body and extremities with a military extreme cold protection clothing ensemble at an ambient temperature of -40°C.

Manual performance and body temperature responses were assessed in a 1-h trial at an ambient temperature (T) of -40°C for 7 male participants (32 ± 14 (mean ± SD) years) wearing a typical military extreme cold protection clothing ensemble. The purpose was to establish duration limited exposure (D) for these conditions, and it was hypothesized that (i) core temperature (T) would remain normothermic, whereas extremity skin temperature (T) would decrease; (ii) decrements of manual performance would be in proportion to decreases of hand T; and (iii) D would be determined by the hand or foot T responses. Linear regression was employed to assess associations of manual performance scores and body temperatures with D assessed using the Required Clothing Insulation (I) model and extremity temperatures in ISO 11079-2007.