Risk factors

Anyone can develop heatstroke, but several factors increase your risk:

• Age. Your ability to cope with extreme heat depends on the strength of your central nervous system. In the very young, the central nervous system is not fully developed, and in adults over 65, the central nervous system begins to deteriorate, which makes your body less able to cope with changes in body temperature. Both age groups usually have difficulty remaining hydrated, which also increases risk.
• Exertion in hot weather. Military training and participating in sports, such as football or long-distance running events, in hot weather are among the situations that can lead to heatstroke.

• Sudden exposure to hot weather. You may be more susceptible to heat-related illness if you're exposed to a sudden increase in temperature, such as during an early-summer heat wave or travel to a hotter climate.

  Limit activity for at least several days to allow yourself to acclimate to the change. However, you may still have an increased risk of heatstroke until you've experienced several weeks of higher temperatures.

• A lack of air conditioning. Fans may make you feel better, but during sustained hot weather, air conditioning is the most effective way to cool down and lower humidity.

• Certain medications. Some medications affect your body's ability to stay hydrated and respond to heat. Be especially careful in hot weather if you take medications that narrow your blood vessels (vasoconstrictors), regulate your blood pressure by blocking adrenaline (beta blockers), rid your body of sodium and water (diuretics), or reduce psychiatric symptoms (antidepressants or antipsychotics).

  Stimulants for attention-deficit/hyperactivity disorder (ADHD) and illegal stimulants such as amphetamines and cocaine also make you more vulnerable to heatstroke.

• Certain health conditions. Certain chronic illnesses, such as heart or lung disease, might increase your risk of heatstroke. So can being obese, being sedentary and having a history of previous heatstroke.