One study showed an average of over 60,000 cases of heat illness per summer seen by emergency departments in the United States. The study showed about 12% of the people affected were admitted to the hospital (an average of 7,678 per year) and there were an average of 46 deaths per year.
The causes of heat exhaustion and heatstroke are similar. The leading cause of both conditions is the body’s inability to cool itself due to hot weather, exercise, or both.
Additional causes are dehydration, alcohol use, and overdressing.
Body’s Failure to Cool Itself
When your body’s internal temperature is not regulating correctly, your body can become unable to cool itself. Being in a hot environment can lead to a rise in your core body temperature after exposure to hot and humid weather for a long period. This is most common in older adults and people with chronic conditions.
Strenuous activity can increase the body’s core temperature, especially if you exercise or work outside in hot weather or a hot room. This often affects people not used to high temperatures or who are not staying hydrated in hot areas.
Dehydration
Dehydration refers to the absence of sufficient fluids in the body. Heat exposure combined with dehydration often leads to heat illness.
Alcohol Use
Drinking alcohol when out in high temperatures can lead to the body not being able to regulate its body temperature. Alcohol combined with hot temperatures can also lead to dehydration. This is because alcohol is a diuretic and in combination with heat, it can cause you to lose body fluids through sweating and urination.
Overdressing
It is important to wear clothing that is suitable for extreme heat. Clothing weights, fabrics, and even color affect sun penetration and how well air circulates over your skin, allowing for sweat to evaporate. When sweat cannot evaporate from the skin, body temperature increases.