To prevent heatstroke, keep your cat indoors when the temperature is 100 degrees or above. If possible, keep them in a room that is air-conditioned or has good air flow. Provide plenty of fresh water for your cat to drink, and make sure they have access to a shady spot to rest. If your cat must go outside, make sure they are only outside for short periods of time and try to avoid taking them out in the middle of the day when the sun is strongest.