• Nausea or vomiting
How your body loses heat
The mechanisms of heat loss from your body include the following:
• Radiated heat: Most heat loss is due to heat radiated from unprotected surfaces of your body. Your head has a large surface area and accounts for about half of all heat loss.
• Direct contact: If you’re in direct contact with something very cold, such as cold water or the cold ground, heat is conducted away from your body. Because water is very good at transferring heat from your body, body heat is lost much faster in cold water than in cold air. Water that is 65 Fahrenheit (18 Celsius) — a relatively mild air temperature — can lead to hypothermia very quickly. Similarly, heat loss from your body is much faster if your clothes are wet, as when you’re caught out in the rain.
• Wind: Wind removes body heat by carrying away the thin layer of warm air at the surface of your skin.
First aid care
• Be gentle: When you are helping a person with hypothermia, handle him or her gently. Limit movements to only those that are necessary. Don’t massage or rub the person. Excessive, vigorous or jarring movements may trigger cardiac arrest.
• Move the person out of the cold: Move the person to a warm, dry location if possible. If you’re unable to move the person out of the cold, shield him or her from the cold and wind as much as possible.
• Remove wet clothing: If the person is wearing wet clothing, remove it. Cut away clothing if necessary to avoid excessive movement.
• Cover the person with blankets: Use layers of dry blankets or coats to warm the person. Cover the person’s head, leaving only the face exposed.
• Insulate the person’s body from the cold ground: If you’re outside, lay the person on his or her back on a blanket or other warm surface.