Symptoms and Complications
Hypothermia can come on very slowly, making it difficult to notice that
it's happening. When the body is cold, it tries to protect itself by shivering.
When hypothermia sets in, the shivering stops, as the body is now trying to
conserve energy. This is one of the first warning signs of hypothermia. You
might also begin to feel clumsy and disoriented as your body temperature drops.
The heartbeat can become irregular and breathing slows down.
One complication of hypothermia is that the heart becomes very sensitive
and can be easily jolted into an irregular rhythm. If you try to rescue
someone with hypothermia, you need to be as gentle as possible to prevent any
sudden movements. As well, emergency personnel will keep an eye on the heart
during the re-warming process to watch for any such irregularities.
How fast the signs of frostbite develop depends on the air temperature,
wind chill factor, and how well the affected body part is protected. It's
possible to get frostbite within minutes during extremely cold conditions.
Mild frostbite (frostnip) makes the skin look white or waxy but the
color returns once the skin is warm again. Once thawed, the skin might turn
red and it could take a while for the redness to go away.
Severe frostbite begins with white or waxy-looking skin but, as the damage
progresses, the color becomes gray or bluish. The cold feeling disappears and
is replaced with numbness and blisters might form. At this point, it's very easy to cause other damage besides the actual freezing.
For example, because you might have lost feeling in a foot that is frostbitten, you might not
feel blisters forming and breaking. A frozen finger could break easily in a
fall, and skin can burn very easily if it's not warmed up properly.
As a frozen body part warms up, the area may swell, itch, burn, and be extremely
painful. Extreme frostbite will turn the skin black, and gangrene may set in. In this case amputation may be needed.