Q: It has been extremely hot and humid in my part of the country most recently. While I think I know the benefits of staying hydrated, sometimes I find myself completely exhausted and having a knot in my groin that tells me it’s time to drink even more than I already do. Can you give me some information on heat exhaustion or heat stroke?

A: Generally speaking, we don’t have to think about cooling our bodies since the body automatically cools itself by sweating and allowing that sweat to evaporate. The body also loses heat by by conduction-like heat loss when sleeping on a cold ground, by being in the wind or in front of a fan, and through other means. However, when an individual is exposed to extreme heat and/or humidity, the body’s natural ability to provide this service can be compromised and can result in heat exhaustion. The first step is often heat cramps which may be the sensation to which you refer, followed by heat exhaustion and on to heat stroke. The cramps may then be followed by general malaise, weakness, lightheadedness, nausea, vomiting, and muscle cramping. During heat stroke, the body no longer sweats, the individual may appear confused and even have a seizure because of excessive bodily temperatures.

Heat cramps follow extended periods of exposure to high temperatures or indulging in physical exercise in less than optimal conditions. Symptoms can include profuse sweating, intense thirst, fatigue and cramping – especially in the stomach, groin area and extremities. Relocating to a shady spot out of the sun, taking in water or drinks that contain electrolytes and resting should stabilize a person and eliminate the symptoms.

Unfortunately, when an individual fails to act on the symptoms, they will worsen and heat exhaustion generally sets in. Muscle cramping, nausea, headache, lightheadedness and skin that is cool and moist to the touch will follow. Treatment is essentially the same as it is for heat cramps and may require intravenous fluids.

Heat stroke is actually a progression of the heat cramps mentioned above and heat exhaustion and is brought on by prolonged exposure to excessively high temperatures with or without strenuous activity. Extreme temperatures can result in impairment of the body’s temperature-regulating abilities when temperatures reach 104 degrees or higher. Left untreated, damage to the brain, kidneys, heart and muscles can occur. An individual may have a seizure, have difficulties explaining his or condition if asked, and may hallucinate. Symptoms may include nausea, vomiting, cramping, confusion, palpitations – all without sweating. This condition will worsen with time if left untreated, increasing the risk of very serious complications.

There are some common situations that can increase a person’s risk of developing heat stroke. Specific medications, including beta blockers for high blood pressure, diuretics, antidepressants and illegal stimulants. Then there are chronic medical conditions such as cardiac disorders and obesity that must be considered.

Heat stroke is a true medical emergency requiring hospital care and intravenous fluids. Initial treatment outside a hospital setting might include immersion in cold water to bring the temperature down or better still, spraying the body with a cool water application, applying ice packs to the groin, armpits and other areas of the body, hydrating, and cooling the individual by placing him or her in the shade or in an air-conditioned environment are essential.

So, now that I have identified the stages of heat-related conditions, hydrate, hydrate, hydrate. Pace yourself. The work or football game will still be there but you have to first recognize the symptoms as they present and second, learn to protect yourself from potential consequences as they occur. Carry water or sports drinks with electrolytes. Carry a water bottle with a spray nozzle that you can mist over you while exposed to the hot sun. Most importantly, listen to your body. Ten minutes under a shade tree will be the best time spent in your day – even if you have to do it more than once. Good luck.