Heat illnesses are easily preventable by taking necessary precautions in hot weather.

Children, elderly, and obese people have a higher risk of developing heat illness. Also, people taking certain medications or drinking alcohol have a higher risk. However, even a top athlete in superb condition can succumb to heat illness if he or she ignores the warning signs.

If the problem isn't addressed, heat cramps (caused by loss of salt from heavy sweating) can lead to heat exhaustion (caused by dehydration), which can progress to heatstroke. Heatstroke, the most serious of the three, can cause shock, brain damage, organ failure, and even death.

The following are common causes of heat emergencies:

• High temperatures or humidity
• Dehydration
• Prolonged or excessive exercise
• Excess clothing
• Alcohol use
• Medications, such as diuretics, neuroleptics, phenothiazines, and anticholinergics
• Cardiovascular disease
• Sweat gland dysfunction