What are the signs of hypothermia?

Hypothermia is when your normal body temperature of 37C (98.6F) drops below 35C (95F).

When your body temperature drops (you begin to feel cold), your automatic response is usually to put more layers of clothes on; become active to warm up; or to move indoors. However, if done of these are possible, your body's natural defenses will try to prevent any further heat loss by:

• shivering, in an attempt to keep you major organs at a normal temperature,
• restricting blood flow to your skin, and
• releasing hormones to generate heat.

What are the signs?

Hypothermia usually occurs gradually, and often you may not even be aware that you need help. The signs of hypothermia depend on two factors:

1. how cold the environment is, and
2. how long you have been exposed to it for.

The symptoms of mild hypothermia include:

• shivering,
• feeling cold,
• feeling that you have no energy,
• feeling that you are less able to tolerate the cold than normal, and
• having cold and pale skin.

The symptoms of moderate hypothermia include:

• uncontrollable (often violent) shivering,
• problems thinking clearly or paying attention to events around you,
• loss of judgement and reasoning,
• feeling confused,
• difficulty moving around or stumbling,
• shaking hands,
• feeling fearful,
• memory loss,
• drowsiness,
• slurred speech, and
• slow, shallow breathing with a weak pulse.

The symptoms of severe hypothermia include:

• losing control of your hands, feet, and limbs,
• stiff muscles,
• unconsciousness,
• shallow or no breathing,
• weak, irregular or no pulse, and
• dilated (enlarged) pupils.

In some cases of severe hypothermia you may also stop shivering.

If you suspect that you, or someone else, has hypothermia call your doctor for further advice. If you suspect severe hypothermia call 911 immediately.