Hypothermia in Dogs: Warm Them Slowly, Never Fast

Warming a freezing dog too quickly can stop its heart. The right answer is blankets and patience, not a hairdryer.

Everything about a cold, shivering dog tells you to warm it up fast. Hot water bottle, radiator, hairdryer, hot bath. It is the most natural response in the world and it is genuinely dangerous.

When you heat the skin faster than the core can keep up, the blood vessels at the surface open, the cold blood held in the limbs floods back to the centre carrying acid and potassium with it, and the heart can stop. It is called rewarming shock, and it is why the veterinary approach to hypothermia is slow, dull and passive.

What to do

1. Get the dog out of the cold into a warm, dry space, and dry it first if it is wet. A wet coat pulls heat away faster than cold air does, so towelling comes before anything else.
2. Wrap it in dry blankets, one underneath and one over. A person sitting close adds gentle, safe warmth.
3. Let the room warm up slowly. Heating on low, car heater rising gradually. Not next to a fire, radiator, heat lamp or hairdryer.
4. If the dog is fully awake and able to swallow, offer small amounts of lukewarm water. Not hot, and not at all if it is drowsy.
5. Ring the vet and go in, even if it appears to be picking up.

Why you go in anyway

This is the second mistake, after warming too fast: assuming a dog that has come round is fine.

Hypothermia damages clotting, the kidneys and the heart in ways that are invisible on the hearthrug and show up hours later. A dog that stops shivering, brightens up and asks for its dinner has not necessarily escaped anything.

For a dog under 5kg, a puppy under about sixteen weeks, or a thin, elderly or already unwell dog, treat any sign of hypothermia as urgent. Small bodies lose heat far faster and run out of reserve much sooner.

The sign everyone reads backwards

Shivering is the body generating heat. It is a mild sign and it is the moment to act.

When a severely cold dog stops shivering and goes quiet and still, that is not recovery. The muscles have run out of fuel to shiver with, and the dog is deteriorating. Quietness after heavy shivering is the point at which things are getting worse, not better.

The full picture, roughly in order:

• Shivering
• Drowsiness, confusion, clumsiness, stumbling
• Cold ears, paws and tail, with fur that feels cold and stiff
• Pale gums
• A slow heart rate or a weak pulse
• Shivering stopping, the dog going still and quiet
• Collapse, unconsciousness

What not to do

No hot water bottles, hot baths, hairdryers, heat lamps, electric blankets on high, or letting a dog lie against a radiator. Beyond rewarming shock there is a second problem: cold skin loses its ability to feel heat properly, so a dog can be badly burned without reacting.

Do not rub or massage the legs to warm them up. It pushes cold blood into the core too quickly and can trigger the same collapse.

Do not give water, food or medication to a drowsy or half-conscious dog. The swallow reflex is depressed and it will go into the lungs.

Do not put the dog straight into a hot car. Slowly rising ambient warmth only.

How dogs get this cold

Long exposure in cold weather, falling into cold water, being wet and out in wind, or being shut outside or in an unheated car. Wet plus wind is the combination that does it fastest, and it does not need to be anywhere near freezing.

Small, thin, old and very young dogs, and breeds without much coat, lose heat quickly and should have their time outdoors limited in genuinely cold weather. A coat is not an affectation on a whippet in January.

Dry a wet dog properly after winter walks rather than letting it dry off on its own, and if you are travelling in cold conditions, keep a dry towel and a blanket in the car. They are the right equipment for this, and the hairdryer is not.

Sources

This article was written using guidance from PDSA, the UK's largest veterinary charity, whose Pet Health Hub is written by its own vets and nurses; and AVMA, the American Veterinary Medical Association, the professional body representing US veterinarians. This guidance is for general information and does not replace a consultation with your own veterinarian. In an emergency, always contact a vet. Read [how we write our health guidance](https://rochsociety.com/how-we-write-our-health-guidance/). Last reviewed July 2026.