There are 3 The other types of heat related illnesses that are of major concern.  Heat Exhaustion, Heat cramps and Heat stroke.

 HEAT EXAUSTION

Heat exhaustion is a condition whose symptoms may include heavy sweating and a rapid pulse, a result of your body overheating. It's one of three heat-related syndromes.

Causes of heat exhaustion include exposure to high temperatures, particularly when combined with high humidity, and strenuous physical activity. Without prompt treatment, heat exhaustion can lead to heatstroke, a life-threatening condition. Fortunately, heat exhaustion is preventable.

 Symptoms:

Symptoms include feeling tired, weak, and dizzy; headache, nausea and possible vomiting. Heavy perspiration; skin feels moist.

 Prevention:

Drink lots of cool water, even more than you think you need, when the weather is hot and humid. (High humidity makes heat injuries more likely because perspiration does not evaporate from the skin as quickly; this causes the body to cool down more slowly.) Water is best; 100% fruit and vegetable juices are good too.

 

Realize that older people are more sensitive to heat and may easily suffer heat-related sickness. Also, anyone with diabetes, heart disease, arteriosclerosis, high blood pressure, or Parkinson’s disease is more sensitive to the effects of heat. Stay in the shade when possible, and remove wool uniform jackets and coats when possible

 HEAT CRAMPS:

Heat cramps are painful, involuntary muscle spasms that usually occur during heavy exercise in hot environments, such as wearing wool in August. The spasms may be more intense and more prolonged than are typical nighttime leg cramps. Inadequate fluid intake often contributes to heat cramps.  Muscles most often affected include those of your calves, arms, abdominal wall and back, although heat cramps may involve any muscle group involved in exercise.

 Prevention:

 Avoid excessive alcohol consumption the night before the event, and drink water before you go to sleep Limit coffee intake the morning of the battle, and drink water or 100% fruit/vegetable juice with breakfast.

 Drink at least 1 liter of water all during the morning of the battle, and do not drink the whole liter just before the event. 

 Drink from you canteen all during the event.  If you are thirsty, you are already getting dehydrated.

               HEAT STROKE                     
Heatstroke is caused by prolonged exposure to high temperatures or by doing physical activity in hot weather. You are considered to have heatstroke when your body temperature reaches 104 F (40 C) or higher. High humidity, certain health problems and some medications increase your risk of heatstroke. So does being a young child or older adult.

Heatstroke occurs if your body temperature continues to rise. At this point, emergency treatment is needed. In a period of hours, untreated heatstroke can cause damage to your brain, heart, kidneys and muscles. These injuries get worse the longer treatment is delayed, increasing your risk of serious complications or death.

If you reach this point it is too late for prevention or First Responder treatment.  Emergency Room intervention is the only course of action.