If a horse is being exercised on hot days, extra care and attention must be given because there is a significant increase in the amount of heat produced by working muscles. Heat production can increase as much as 50% during intense exercise as compared with heat production when the horse is at rest. A horse increases its sweating rate to move more blood to the capillaries under the skin and breaths much harder in an effort to release this build-up of heat.

      The most commonly observed signs of "Heat Stress" are profuse sweating, rapid breathing, and a rapid heart rate. Some horses have a condition leaving them little or no ability to produce sweat, these horses are called "Anhydrotic". Since heat loss is mainly dependent on sweating and its evaporation, anhydrotic horses are prime candidates for heat stress. It's important to know if your horse falls at risk due to this condition, and take proper precautions to protect it from overheating.

      When you work or exercise your horse in hot weather, watch carefully for the signs of "Heat Stroke" which can include; skin that is dry and hot, a pulse and respiratory rates much higher than normal and unusually high rectal temperatures. "Heat stroke is life threatening," If you suspect that your horse is suffering from heat stroke, call your veterinarian immediately! While you are waiting for your vet, move the horse to a shady area with fans or wind to provide cool ventilation. Spray cool water on the horses legs and body to help lower the internal temprature. In critical situations, ice packs or cold water soaked towels should be placed on legs and other areas that exhibit large veins surfaced on the horse. (if cold towels are used, make sure to change them often because the horses extreme heat will quickly turn the cold water hot) Normally, a horse's rectal temperature is around 101 degrees fahrenheit, if the rectal temprature is around 104 degrees for any length of time, it is characteristic of a life-threatening situation.

      When a horse is suffering from heat stress, stop working the horse and begin cooling the animal's body with fans and shade to help stop the onset of heat stroke. Also, pay careful attention to make sure that the horse doesn't become dehydrated during long bouts of exercise, large amounts of fluid can be lost through sweat. In most cases, horses should be allowed to drink as often as they desire, even during exercise, unless they are showing signs of heat stress. A "hot" horse has the chance to colic if given lots of water while they are hot. Small amounts of water should be offered to the horse in frequent intervals before, during and after exercise.

      A simple test that can be used to determine marginal water loss in a horse is the pinch test. When a section of skin on the neck or shoulder is pinched, the skin recoil will be immediate in normally hydrated horses. Dehydration will delay skin recoil.

      It is important to make sure the horse is properly cooled-down following exercise work-outs. The built up heat must be released from the horse's body through respiration and sweat. Heat loss through sweat requires moving air and evaporation. Walking a hot horse allows the air movement to continue to help evaporate heat, if left standing still, the lack of air movement could force the internal temprature to rise even higher. Air flow is vital to remove heat off the horse's body. The length of cool-down will depend on the amount of work, the environmental conditions and the individual horse.

      Horse owners who know the signs of heat stress in horses can help prevent heat stroke in their animals, so becomming aware, can reduce the chance of injury, or even worse, death. If you use common sense and good judgement, this all can be avoided, so watch for the signs!