Hypothermia: Common Questions Answered
Hypothermia: straight answers to the questions people actually ask, with the figures behind them.
A dangerously low body temperature caused by losing heat faster than the body can produce it.
Key takeaways
- Definition: body temperature below 95°F (35°C)
- Signs in adults: shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech, drowsiness
- Most useful single change: Dress in layers and cover your head, hands and feet in cold weather.
- Commonest mistake: Drinking alcohol to "warm up".
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
What is Hypothermia?
A dangerously low body temperature caused by losing heat faster than the body can produce it.
Why does it matter?
It can happen indoors as well as outdoors, and it affects thinking, so people may not realize it is happening.
Signs in adults for Hypothermia?
Shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech, drowsiness.
Signs in babies for Hypothermia?
Bright red, cold skin and very low energy.
Higher risk for Hypothermia?
Older adults, babies, people who drink heavily and people outdoors for long periods.
Can occur for Hypothermia?
Even above 40°F (4°C) if a person is chilled by rain, sweat or cold water.
What is the single most useful thing to do?
Dress in layers and cover your head, hands and feet in cold weather.
What is the most common mistake?
Drinking alcohol to "warm up".
When should I see a doctor?
Call 911 if a person's temperature is below 95°F or they are confused, very drowsy or unresponsive. If the person has no pulse, start CPR while waiting for help.
More questions, answered
Can you get hypothermia indoors?
Yes. Older adults, babies and people who are ill can develop hypothermia in a cold house, even when the temperature does not seem extreme. Long exposure to mild cold can be enough. Keeping the home heated and wearing layers indoors help prevent it.
Should I rub someone's arms and legs to warm them up?
No. Rubbing the limbs does little to warm the core and can damage cold skin. Focus on warming the center of the body first, with dry clothing, blankets and warm packs on the chest, neck, armpits and groin, and handle the person gently.
Is a hot bath a good way to rewarm?
For a mildly cold but alert person, a warm, not hot, shower or bath can be comfortable once wet clothing is off. For anyone with more than mild hypothermia, call 911 instead, because rapid warming of the skin can cause blood pressure to drop and strain the heart.
Why does a hypothermic person stop shivering?
Shivering uses a lot of energy and stops as the body runs low on fuel or as temperature falls further. Stopping shivering while still cold is a warning sign that hypothermia is getting worse, not better.
How fast can cold water cause hypothermia?
Water draws heat from the body much faster than air at the same temperature. In cold water, the first danger is the gasp and fast breathing of cold shock, then muscle weakness that makes swimming hard. Hypothermia follows. Wearing a life jacket is the most important protection.
Is it true that you are not dead until you are warm?
Emergency teams follow this principle because very cold bodies can survive conditions that would otherwise be fatal. They will often continue CPR and rewarming for a long time. As a bystander, start CPR if there is no pulse and keep going until help arrives.
Related topics
- CPR and Defibrillation: What the Evidence Actually Says (Emergency Care)
- Sun and Heat Abroad: What the Evidence Actually Says (Travel Health)
- Dry Skin: Sorting the Evidence From the Noise (Skin Health)
- The Evidence on Fever, Without the Hype (Immunity)
Where to go next
- Hypothermia: A Practical Checklist
- Popular Beliefs About Hypothermia, and What Is Actually Published
- Hypothermia — the reference entry
- Weather Safety: The Complete Guide
- Frostbite: What Published Guidance Supports
- Wildfire Smoke: What Published Guidance Supports
When to speak to a doctor
Call 911 if a person's temperature is below 95°F or they are confused, very drowsy or unresponsive. If the person has no pulse, start CPR while waiting for help.
Where this comes from
- CDC — Preventing Hypothermia
- National Institute on Aging — Cold Weather Safety for Older Adults
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.
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