How a cat's cooling system actually works
Cats are built for warmth and only modestly equipped for heat. They sweat through their paw pads and nowhere else that counts; the rest of their cooling is behavioural — seeking shade, going still, stretching out on a cool surface, and grooming so that evaporating saliva draws heat off the coat. Unlike dogs, cats do not normally pant. That single difference is the one to remember, because it turns panting from a weather report into an alarm. In a heatwave your job is to supply what her instincts are looking for: cool surfaces, still air she can choose, water everywhere, and no trapped-hot places she cannot leave.
Build the cool house before the heat peaks
Start in the morning, before the sun is on the glass. Close curtains or blinds on sun-facing windows, and open windows only on the shaded side and only where she cannot get out — a window opened for air is both a fall risk and an escape route, so use screens or restrictors. Give her the run of the coolest rooms: the tiled bathroom or kitchen floor is usually her own first choice. A fan in the room she uses helps by moving air, and it does not need to aim at her. Never leave her in a car, a conservatory or a sunroom, all of which become ovens; and before you lock sheds and greenhouses at night, check inside — cats slip in at noon for the shade and are still there, in the heat, at dusk.
Water and food tactics that actually help
Place several bowls of fresh water in shady spots around the house and refresh them often; many cats drink more from a bowl set away from their food. An ice cube in a bowl gives her something cold to lick and paw at, and a frozen bottle of water wrapped in a towel makes a cool spot to lie against. Wet food contributes moisture, but in heat it spoils fast — serve smaller portions more often and lift what is left rather than leaving it down. A slight dip in appetite on the hottest days is normal; a cat who stops drinking is not. Brush loose coat out daily, since a thick undercoat traps heat against the skin. White and pale-eared cats burn in strong sun, so keep them in through the middle of the day.
The signs that change the plan — act the same hour
Heatstroke in a cat escalates fast, and the signs are distinctive: panting or open-mouth breathing, drooling, a bright-red tongue, restlessness that tips into lethargy, unsteady walking, and vomiting. If you see them, move her to the coolest room, offer water without forcing it, wet her paws and belly with tepid — never iced — water, and phone the vet immediately; this is an emergency, not a wait-and-see. Give extra thought to the vulnerable: elderly cats, kittens, flat-faced breeds and overweight cats all overheat sooner. Should the worst happen on the hottest day of the year and she gets out, the Lost Pet Alert System on KinsLe — free in every profile — can display her alert on a map, and whoever spots her can get in touch through it.