Which situation may expose someone to the risk of hypothermia?

Spending prolonged time in cold water significantly increases the risk of hypothermia. When a person is immersed in cold water, the body loses heat much more rapidly than it does in cold air due to water's higher thermal conductivity. This rapid heat loss can decrease the core body temperature to dangerously low levels. Prolonged exposure without adequate insulation or warmth can lead to hypothermia, a condition characterized by an abnormally low body temperature, which can affect the body's ability to function properly.

In contrast, being indoors in a warm environment and wearing appropriate winter clothing would help maintain body heat and prevent hypothermia. Engaging in physical activity during sunny weather typically raises body temperature rather than lowers it, further reducing the risk of hypothermia.