Rat temperature guide: too hot, too cold and just right

What is the right temperature for pet rats?

Aim for 19 to 24°C (66 to 75°F). The good sources overlap rather than agree exactly, so here is what each says:

We follow the overlap of the two RSPCA figures, 19 to 24°C (66 to 75°F), as the target, and treat the MSD range as the outer limits. That is normal room temperature in most homes, so for most of the year you don't need to do anything special. What matters more than the exact number is steadiness: PetMD and the RSPCA both stress that rats cope badly with big swings.

Why rats struggle in the heat

Rats can't sweat and they can't pant. The MSD Veterinary Manual and RSPCA Australia explain that they cool down by sending more blood to the skin of the tail, and also the ears and feet, and by spreading saliva over their fur while grooming. That works in a mild room and fails fast in a hot one. Overcrowding makes it worse: the MSD manual singles out crowded cages as the highest heat risk.

A cage that feels fine to you can still be too hot for the rats inside it. Sun through a window, a radiator next to the cage, or a solid-sided tank that traps warm air can all push the cage well above room temperature. PetMD warns against glass and plastic tanks because their solid walls block airflow; our guide to the best rat cages explains what to choose instead.

Signs your rat is too hot

RSPCA Australia lists the signs in the order they usually appear:

• Less active than usual, lying about in the day and at dusk.
• Stretched out flat on the belly or back, legs spread, to lose heat.
• Growing weakness and wobbliness.
• Drooling or a wet chin.
• Refusing food.
• Collapse, unresponsiveness or fits: an emergency.

Stretching flat on a cool shelf on a warm afternoon is normal, but it is also your cue to start cooling the room. Don't wait for drooling or weakness.

How to keep rats cool in hot weather

1. Check the thermometer. Put a cheap room thermometer next to the cage, not across the room, so you read the temperature the rats actually feel.
2. Move the cage. Shift it to the coolest room, away from windows and out of direct sun. The RSPCA advises this whenever summer temperatures rise.
3. Block the sun and heat. Close the curtains or blinds on the sunny side and switch off lamps and electronics near the cage.
4. Move the air. Run a fan in the room, pointed so it moves air around the cage rather than blowing straight onto the rats, and use air conditioning if you have it.
5. Give them cold spots. RSPCA Australia suggests ceramic tiles, frozen water bottles wrapped in a cloth, or cold packs, plus shady hides, so each rat can choose where to lie.
6. Keep water coming. Check every bottle morning and evening, and add an extra one. Water-rich foods such as cucumber, melon and strawberries help too.
7. Thin out the fleece. Take out a few of the thicker fabric beds and leave lighter ones, so there is nowhere warm to get stuck in.

What to do if your rat has heatstroke

Act straight away, then get to a vet. RSPCA Australia gives this first aid:

1. Ring the vet. Tell them you are coming with a rat you think has heatstroke, so they are ready.
2. Wet the fur. Dampen the rat's fur with tepid or lukewarm water, never cold.
3. Cool the hot spots. Hold a cold pack wrapped in a thin cloth against the neck, armpits or groin, or lay the rat belly-down across a wrapped pack.
4. Fan them. Moving air over damp fur helps the water carry heat away.
5. Travel cool. Keep the rat damp and on the wrapped pack, with the car's air conditioning on, all the way to the vet.

Can rats get too cold?

Yes. Rats are hardy in a cool room, but cold, damp and draughts together are a real risk. Blue Cross says pet rats must live indoors because it is too cold for them outside, and the RSPCA rules out conservatories, garages and sheds, which swing between cold nights and hot days. Below 18°C (64°F) you are under the MSD manual's safe range.

Our sources don't list cold signs for rats, but the ones owners watch for are huddling tightly all day, shivering, cold ears and feet, a fluffed-up coat and moving less. A rat that is cold and also sneezing, breathing noisily or off its food needs a vet, because cold and damp make breathing problems worse. See our guide to rat respiratory infections for what to watch.

How to keep rats warm in winter

• Keep the cage away from draughty doors, windows and outside walls, as Burgess advises.
• Add extra bedding and nesting paper for burrowing, and keep it dry: damp bedding chills fast.
• Give plenty of covered hides and fleece beds so the group can huddle.
• Keep at least two or three rats together; they warm each other.
• Check bottles often if the room gets very cold, so a spout can't freeze or block.
• Expect them to eat a little more in winter, as Burgess notes, and keep weighing weekly.
• Never put the cage right next to a radiator, fire or wood-burner. Burgess also warns about fumes from non-stick pans, aromatherapy oils and stoves.

Hammocks and fleece beds help too; our rat hammock guide covers what to look for, and our rat bedding guide covers what goes on the floor.

Rats that need extra warmth

Our hairless rat care guide goes into skin care and warmth in detail, and our rat breeds and varieties guide explains which coats are thinnest.

Travelling with rats in hot or cold weather

Rats heat up or chill fastest in a car or a carrier. Never leave them in a parked car, even for a few minutes. In summer, travel in the cool of the morning with the air conditioning on; in winter, cover part of the carrier with a towel and warm the car first. Our guide to rat carriers and travel cages covers what to pack.

For everything else about keeping rats, start at our pet rat care hub.