Heat stress and hyperthermia in cats is a genuine welfare emergency that can cause irreversible organ damage within minutes of onset.
Feline hyperthermia causes rapid deterioration that requires emergency treatment. Unlike dogs, cats rarely pant visibly until severely affected, making early recognition difficult. Affected cats become lethargic, drool, breathe rapidly, and may collapse. Rapid external cooling with cool (not cold) water is the immediate welfare intervention before veterinary transport. Cats should never be left in hot cars, conservatories, or other enclosed spaces during warm weather. Indoor cats must have access to cool areas, fresh water, and ventilation. Brachycephalic breeds are at substantially higher risk and require extra vigilance during warm weather. The welfare impact of heatstroke extends to organ damage that may affect quality of life permanently if the animal survives.