What actions should be taken to prevent hypothermia in casualties?

Covering casualties with warming blankets or clothing while protecting them from the wind is vital in preventing hypothermia. This action addresses the key factors that contribute to heat loss in the body. When a person is exposed to a cold environment, they lose body heat through conduction, convection, and evaporation. By using warming blankets or additional clothing, the insulation of the body is improved, reducing heat loss. Protecting from wind further prevents the cooling effects caused by wind chill, which can significantly lower body temperature.

Other options do not adequately address the prevention of hypothermia. Encouraging movement might seem helpful by generating body heat, but it could also lead to increased perspiration, which in turn can lead to more rapid heat loss if the individual becomes wet. Keeping casualties in direct sunlight could also pose risks, as exposure to fluctuating temperatures without proper insulation may not efficiently regulate core body temperature. Fluid rehydration is important for overall health but doesn't have a direct impact on preventing heat loss in cold environments.