Cooling Options for Shipboard Personnel Operating in Hot Environments

摘要

DRDC Toronto was asked by the Director of Maritime Health Services to provide information and guidance about the use of cooling vests for shipboard personnel exposed to hot environments. A review of the literature suggested that three options might be available; liquid- or air-cooled systems; phase change material cooling vests; and, extremity cooling. The Steele Vest, which uses water and corn starch as the phase change material, is currently in use by the US Navy. Laboratory studies have shown that the use of this vest will effectively double tolerance times during light exercise in hot environments (in excess of 40C). Extremity cooling through the immersion of the hands and forearm in cool buckets of 10C or 20C water is currently recommended for use by the UK Royal Navy. As long as 20-30 minute rest periods can be scheduled each hour this is as effective as the use of continuous cooling with the Steele Vest. The use of a liquid-cooled suit with a battery-operated pump has been shown to reduce the heat strain of boiler room personnel. The use of an ice vest or alternative phase change material cooling vest would be most effective for personnel performing light exercise such as cage operators involved in the movement of food and equipment, personnel manning the 50-calibre machine guns, brow staff, and firefighters standing in the hangar lobby. The use of forearm and hand immersion in buckets of cool water may provide a better alternative for boarding parties than the cooling vest. Rotation of personnel could be implemented to allow forearm and hand immersion to occur every 30 minutes for a 20-30 minute period. Liquid-cooled suits should be considered as an option for engine stokers. Other factors such as maintaining proper hydration and a high level of cardiovascular fitness during long operations at sea are also critical for enhancing performance in the heat.