A Comparison of Mountain Rescue Casualty Bags in a Cold, Windy Environment

Objective. - To help the Mountain Rescue Association of Scotland find the best protective mountain rescue casualty bag in cold and windy conditions. The study investigated how 3 different casualty bags (labeled Bag 1, Bag 2, and Bag 3) performed in a cold (-10°C, dry bulb), windy (wind speed 3.0 m.s^-1) environment using physiological and subjective responses of the participating subjects. Methods. - Eleven male subjects, aged 23.4 ± 4 years, percentage body fat 15.5 ± 2 (mean ± SD). Each participated in a total of 3 tests (1 for each bag). The tests were scheduled to last 60 minutes. Core and skin temperatures (skin values were measured on the arm, chest, thigh, and calf, and a mean skin temperature was calculated) were measured during the tests. Heart rate, oxygen consumption (Vo₂), and subjective cold perception ratings were also recorded at regular intervals throughout the test duration. All variables except for Vo₂ and cold discomfort were adjusted for baseline. Results. - There was a significant difference in the mean response between the bags for the following variables: Arm, chest, thigh, calf, mean temperature, and cold discomfort. Conclusions. - All 3 bags showed limited ability to protect the subjects in cold, windy conditions. However, the study shows that Bag 2 offered the least protection against the imposed environment. It is difficult to differentiate between the other 2 bags, because Bag 1 performed better than Bag 3 for arm, calf, and mean temperatures, while Bag 3 outperformed Bag 1 for chest and thigh temperatures and cold discomfort scores.