A sleeping bag is important in cold conditions because it helps the body stay warm while sleeping. At night, temperatures drop and the body loses heat quickly. A sleeping bag traps body heat and creates a warm layer of air around the body, protecting it from cold air.

Sleeping bags also protect from cold ground, wind, and moisture, which can make a person feel much colder. By keeping the body warm and dry, a sleeping bag prevents illnesses like hypothermia and helps a person sleep safely and comfortably in cold weather.