Profuse sweating, rapid breathing, and rapid heart rate are indications that the horse is stressed and needs to be moved to a shady area, allowed to cool down, and given water to combat dehydration.

If the horse cannot be cooled down, the nervous and muscular systems will cease to function normally. When these systems stop functioning, heat stroke is inevitable unless measures are taken to cool the horse down and replace fluids lost because of sweating. If heat stroke is suspected, the veterinarian should be called immediately and steps taken to cool both the horse and the environment.

Horses that are affected by anhydrosis (absence of sweating) are extremely susceptible to heat stroke, and special care should be taken with them since the most important mechanism for heat dissipation in horses is evaporation through sweat.

In addition, horses that are unfit or overweight are more susceptible to heat stroke and exhaustion than more fit and lean horses.

If your horse shows signs of heat stroke, immediately move the horse to a cooler, shady area, and call the veterinarian. While waiting for the vet, cool water may be sprayed on the horse's legs and body, or towels soaked in cool water may be wrapped around the horse's legs and other areas that exhibit large veins.

In a critical situation, ice packs may be placed on legs. Fans to circulate the air may be used, and horses should be allowed to drink small amounts of water at frequent intervals. Walking the horse slowly will allow air movement to continue to help evaporate heat.