A Cornish Rex has only the soft undercoat layer most cats bury beneath guard hairs, and that missing outer coat changes his heatwave risks in both directions: he feels heat directly on his skin, and he has very little insulation to slow it reaching him. Add a lean, high-energy build that generates plenty of its own warmth, and this breed needs the coolest spot in the house claimed early.
Give him cold surfaces, not just cool air
A Cornish Rex regulates himself by sprawling. Watch where he chooses: most will abandon soft bedding in a heatwave for a tiled bathroom floor, a stone hearth, or the cool side of a leather sofa. Work with that instinct rather than against it. Clear a stretch of tile for him, lay a cooling mat in his favourite doorway, and make sure at least one of those spots sits in shade all day, not just in the morning.
Fans help him only if he can also leave the moving air; a fan aimed at a closed crate or a corner he cannot exit is a hazard, not a comfort. Keep one room as the cool base — curtains shut against the sun, door open so he can come and go — and let him rotate between surfaces as each one warms under him.
Water in more places than usual
His normal single water bowl may not be enough when the route to it crosses a sun-baked hallway. Put a second bowl in the cool room and refresh both more often than usual, since warm, stale water discourages exactly the drinking he needs to do. Many Cornish Rex cats eat eagerly and stay slim, so do not be tempted to push extra food on a hot day; smaller, cooler meals served in the evening suit a heatwave appetite better.
Never leave him in a parked car, a conservatory, or a closed room that catches afternoon sun, even briefly. Rooms like that climb in temperature far faster than the shaded spaces he chooses for himself, and a thin-coated cat has no buffer while it happens.
Watch a Rex-specific set of warning signs
Heat trouble in a Cornish Rex can look like restlessness first: pacing, stretching out then moving again, unable to settle on any surface. Rapid breathing, panting with the mouth open, drooling, or ears that feel very hot and look flushed are firmer warnings, and a cat who becomes wobbly, vomits, or goes limp is an emergency — cool him gently with room-temperature water on his paws and belly while you contact a veterinary clinic immediately, and do not wrap him in wet towels, which trap heat against that unprotected skin.
Sunburn deserves a mention for this breed too. A Rex who suns himself on a windowsill can burn on the ears and nose through that fine coat, so move his midday sleeping spot out of direct glass-filtered sun.
Plan for the next hot spell while this one is fresh
Note which room stayed coolest, which surfaces he actually used, and how he behaved at the peak of the heat. Those notes turn next summer's guesswork into a routine, and they matter if a vet ever needs to know how he responds to heat.
Storing those observations alongside his vaccination and vet-visit records in KinsLe's Pet Passport keeps the whole picture in one portable packet, ready to show any clinic that treats him during a hot spell.