Hypothermia After Cold Water: Signs and First Steps

Hypothermia means the body's core temperature has dropped below 95°F, and after a fall into cold water it usually comes later than cold shock. Watch for shivering, confusion, fumbling hands, slurred speech and drowsiness, call 911, move the person somewhere warm, remove wet clothing and warm them gently, core first.

This page is about the minutes and hours after someone gets out of cold water. It isn't a substitute for medical care or a first aid course. It explains what to look for and what to do while help is on the way.

95°F

Hypothermia comes later than cold shock

There are two different dangers in cold water, on two different clocks.

• Cold shock hits in the first minutes: gasping, fast breathing and loss of control. It causes most early drownings. See cold water shock.
• Hypothermia builds more slowly. The National Weather Service (NWS) says the onset of hypothermia begins when core body temperature drops to 95°F (opens in a new tab), after the first minutes of cold shock.

The National Center for Cold Water Safety (NCCWS) says it takes about thirty minutes of immersion for an adult of average size to develop hypothermia, even in near-freezing water (opens in a new tab), and that children, with their smaller body size, cool much faster than adults (opens in a new tab). It adds that most victims die from cold shock and incapacitation long before hypothermia becomes an issue (opens in a new tab). The Minnesota DNR's records show the same pattern for ice: of 269 ice-related deaths since 1976, only 5 were from hypothermia (opens in a new tab).

So if someone survives a fall into cold water, hypothermia is often the danger that's left. And it can keep getting worse after they're out. NWS warns: even removed from cold water, a victim's core temperature can continue to drop to dangerous levels (opens in a new tab). This is sometimes called afterdrop.

Signs to watch for

CDC lists these warning signs of hypothermia (opens in a new tab):

NCCWS notes that shivering is an important early warning sign that you're losing too much heat (opens in a new tab). It also warns that it can be very difficult to tell the difference between someone who is badly chilled and someone who has hypothermia (opens in a new tab). Don't wait to be sure. Treat anyone who has been in cold water and shows these signs as an emergency.

CDC says: if you notice any of these signs, take the person's temperature. If it is below 95°F, the situation is an emergency, so get medical attention immediately (opens in a new tab).

Call 911, and what to do while you wait

These steps are the ones NWS shares, developed by the American Red Cross (opens in a new tab):

1. Call 911 or the local emergency number. (opens in a new tab)
2. Gently move the person to a warm place. (opens in a new tab)
3. Monitor breathing and circulation. Give rescue breathing and CPR, if needed. (opens in a new tab)
4. Remove any wet clothing and dry the person. (opens in a new tab)
5. Warm the person slowly by wrapping them in blankets or by putting on dry clothing. (opens in a new tab)
6. Hot water bottles and chemical hot packs may be used. Wrap the person in a towel or blanket before applying. (opens in a new tab)
7. Warm the core first (trunk and abdomen), not the extremities (hands, feet). (opens in a new tab)

CDC adds that you should warm the center of the body first: chest, neck, head and groin (opens in a new tab), and that warm drinks can help increase body temperature, but do not give alcoholic drinks, and do not try to give beverages to an unconscious person (opens in a new tab). If the person is unresponsive and not breathing normally, CDC says to get emergency help right away and start CPR (opens in a new tab), and keep warming them. Learn CPR before you need it: see drowning emergency: the first minutes.

Handle them gently, and keep them lying down. NCCWS explains that some people collapse just before, during or after rescue from cold water, and that the safer position for the victim is horizontal (opens in a new tab). When pulling someone into a small boat, it advises you to have them lie down as soon as possible (opens in a new tab).

What not to do

• Don't warm them too fast. NWS says do not warm the person too quickly. Do not immerse the person in warm water. Rapid warming may cause dangerous heart arrhythmias (opens in a new tab).
• Don't start with the hands and feet. Warm the core first. The Minnesota DNR explains that cold blood trapped in the extremities can come rushing back to the heart after rewarming begins (opens in a new tab), which can cause a dangerous heart rhythm.
• Don't give alcohol. CDC is clear: do not give alcoholic drinks (opens in a new tab).
• Don't give drinks to someone who isn't fully awake. CDC says do not try to give beverages to an unconscious person (opens in a new tab).
• Don't decide they're fine because they're out of the water. Body temperature can keep falling. Keep watching them, and let medical professionals check them.

How to prevent it

Hypothermia after cold water is mostly prevented by not ending up in cold water unprotected:

• Wear a life jacket on every boat, kayak and paddleboard, and on natural ice. It keeps you afloat while you get out or wait for help.
• Dress for the water, not the air. NWS says always dress for water temperature, not for air temperature (opens in a new tab). See cold-water paddling.
• Have a plan to get warm fast. NWS says that after escaping cold water, you should get into a warm, dry, protected environment as quickly as possible (opens in a new tab). On a winter or spring trip, pack dry clothes and a blanket where you can reach them.

What you can do today

• Save CDC's list of hypothermia signs in your phone, and share it with your family.
• Pack a dry bag with warm clothes, a hat and a blanket for any trip near cold water.
• Take a first aid and CPR course that covers cold emergencies.
• Teach everyone the warming rules: gently, core first, no warm bath, no alcohol.

If the person fell through ice, read what to do if you fall through ice. For any fall into cold water, see what to do if you fall into cold water.