"Dew Point": How a Dog's Truffle Cools Its Brain đĄïžđ
Updated 17 October 2026
In short: dogs barely sweat: they cool mainly by evaporation in the airways, through panting and air flowing over the moist lining inside the nose. This cooled blood even helps keep the brain cooler during exercise (Baker and Chapman, 1977). The outer nose itself plays a minor role in cooling; it's more about catching odours and sensing heat. Short-nosed breeds cool down less well.
How does a dog get rid of heat?
| Mechanism | How it works | Importance |
|---|---|---|
| Panting | Fast, shallow breathing: water evaporates from the tongue, mouth and airways | Main |
| Nasal lining | Air breathed in through the nose cools the moist lining of the nasal turbinates | Important |
| Radiation, contact | The dog lies on a cool floor, belly exposed | Supporting |
| Paw pads | A few sweat glands | Minor |
Keeping the brain cool: in a running dog, venous blood cooled in the nose passes close to the arteries supplying the brain and cools them. Measurements showed the brain stayed cooler than the rest of the body during exercise (Baker and Chapman, 1977).
What does the wet outer nose really do?
The wet nose is the dog's main radiator.
FALSEThe nose surface is small. Cooling mainly happens through panting and inside the nose.
The nose can sense heat from a distance.
TRUEDogs spotted an object only slightly warmer than the room from about 1.6 m away (BĂĄlint et al., 2020). Cooler than the surrounding air, the nose is thought to sense this faint radiation.
A warm nose means fever.
FALSENose temperature isn't reliable. Only a thermometer measures fever.
To learn all about the nose, read the mystery of the nose print.
How can you help your dog in hot weather?
- Go out when it's coolEarly morning and late evening; put your hand on the tarmac: too hot for you, too hot for its pads.
- Water at all timesOn walks too, with a dog water bottle.
- Breathable gearA Y harness keeps the throat and chest free; avoid covering vests in the heat.
- Cool the bodyWet the belly and legs with cool, not ice-cold, water.
Heatstroke: heavy panting, very red tongue, thick drool, staggering or vomiting: move the dog to shade, wet it with cool water and call a vet immediately. Short-nosed breeds (bulldogs, pugs) are most at risk.
See also keeping your dog hydrated.
Frequently asked questions
How does a dog cool down?
Mainly by panting and evaporation in the nose and airways. It sweats very little.
Do dogs sweat through their paws?
A little, through the pads, but it plays a minor role in cooling.
Why do bulldogs cope badly with heat?
Their short muzzle reduces the nasal lining and hinders breathing, so they cool down less well.
Should I wet the nose in summer?
Not really. Offer cool water and wet the belly and legs instead.
Sources
- Baker M.A., Chapman L.W. (1977). Rapid brain cooling in exercising dogs. Science 195(4280), 781-783.
- BĂĄlint A. et al. (2020). Dogs can sense weak thermal radiation. Scientific Reports 10, 3736.