Sometimes, it’s just too darn hot. Extreme heat, especially when coupled with exertion, can put a terrible strain on the body. Occasionally, it’s enough to make the hypothalamus go haywire and send the body’s temperature-control system into turmoil.

The hypothalamus is a cherry-sized part of the brain that serves as the body’s thermostat. Thanks to the hypothalamus, the body switches on its temperature regulators, such as sweating and shivering, to protect us from extreme heat or cold. When the hypothalamus is not able to produce the desired responses to keep the body from overheating, however, the result can be heat illness.

There is a progression of  symptoms associated with heat illness. It may start with heat cramps in the thighs and buttocks, then move on to a headache and dizziness. In extreme  cases, there may be vomiting, disorientation, a dangerous drop in blood pressure, and even death.

Symptoms of heat exhaustion – headache, nausea, profuse sweating, fatigue, feeling faint – are considered middle range. In other words, you’re not doing too well, but you’re not as bad off as someone with heatstroke, which is considered the most severe and the most life-threatening of the heat illnesses.

Still, heat exhaustion is nothing to take lightly. “It’s the first step on the road to having heatstroke,” says Ronald Shelton, M.S., a certified athletic trainer in Rockford Illinois. “if you get heatstroke, the hypothalamus shuts down. That’s when you have somebody going into shock.”

Heat exhaustion affects the elderly more than younger people since they do not adjust as well as young people to sudden changes in temperature. Add to that the chronic medical condition that changes their normal body responses to heat, not to mention the effects of prescription medicines that impair their body’s ability to regulate its temperature or that inhibit perspiration.

Here’s what to do to keep out of danger:

Preload with water. James Rogers, M.D., an adolescent and sports medicine physician at Virginia Mason Medical Center and clinical associate professor of pediatrics at the University of Washington School of Medicine, both in Seattle, recommends drinking a full pint of water before beginning an activity in the sun. “Preloading gives you a better ability to sweat,” he says.

Don’t wait for thirst. Waiting until you feel thirsty is courting danger, says Shelton. “Once the body’s thirst mechanism kicks in, it’s already too late.” Drink plenty of water before, during and after the activity, whether or not you feel thirsty. Nina L. Turner, Ph.D., a research physiologist at the National Institute for the Occupational Safety and Health (NIOSH) recommends drinking five to eight ounces of water every 15 to 20 minutes during the activity, or as long as you’re sweating profusely.

Weigh yourself. Turner says it’s easy to believe you’ve satisfied your need for water when your body actually is still dehydrated. One way to make sure replace the water your body lost through sweat is to weigh yourself before and after an event. Any difference in weight represents lost water – water needs to be replaced.

Make it cool, not cold. While you may be craving an icy cold drink of water, you’re betting off opting for one that’s just cool. “If it’s really cold, that inhibits gastric emptying of the fluid,” says Turner. In other words, your body won’t be able to use the water quickly to fulfil its needs, including maintaining blood volume.

Take frequent breaks. If you have to work or perform in the heat, avoid serious problems by taking frequent breaks – preferably including a cool drink – in a cool spot.

Don’t be fooled. The symptoms of heat exhaustion sometimes can fool a victim into believing that it’s a case of the flu. If your flulike symptoms of nausea, headache, and weakness coincide with overexposure to heat, it’s probably not the flu at all. Get out of the heat and start replacing liquids.

Step into the shade. Moving out of direct sunlight or into a cooler environment, such as an air-conditioned building, may bring relief by lowering the body’s core temperature, says Turner.

Get horizontal. If you start to experience symptoms of heat illness, lie down with your feet elevated. If possible, do so in a cool place.

Use ice with caution. Early symptoms of heat illness, such as muscle cramps may be helped by applying ice to the muscles. Putting ice bags across the major muscles helps cool the body’s core temperature, as well, says Shelton. But he warns that too rapid cooling could worsen a person’s condition and may even contribute to shock.

Fan yourself. Air blowing against skin helps dissipate heat, says Shelton. Turn on a fan or fan yourself with newspaper, paper plate, or whatever handy. This is only effective, however, if the air is relatively cool. It’s not much help to blow hot air on someone with a heat illness.

Wear cool duds. The type of fabric and the fit of your clothing can be a factor in how heat affects you. Loose cotton clothing is the best choice on a hot day. “Cotton is an airy fabric that breathes and allows the body to dissipate heat better,” says Shelton.

Lighten up. Wear light-colored clothing, says Shelton. Darker colors absorb heat.

Don’t strip. Going shirtless may look cooler, but you’ll end up hotter that if you were wearing a light, loose-fitting top. Wearing a shirt helps wick away perspiration and heat from your skin. “If you didn’t wear any shirt at all, your body couldn’t get rid of the heat as efficiently,” says Rogers.

Just say no. Say no to alcohol, particularly before having to exert yourself in the heat. “You’re usually dehydrated after moderate alcohol consumption,” says Turner. “Dehydration is a predisposing factor for heat exhaustion.”

Lose weight. Obese people are more susceptible to heat illnesses. “The bigger you are, the ore heat you’ll produce,” says Rogers. Know your medications. Several common medications, including propranolol, may mask signs of heat exhaustion or make you more susceptible to it. Ask your doctor or pharmacist whether any medication you may be taking could have this effect and what precautions you can take.

This information was taken from Centers for Disease Control and Prevention and The Home Remedies Handbook.