By the American Heart Association

SAN DIEGO - Strenuous physical activity, even running errands, leads to heat-related illness and can turn deadly, says the American Heart Association in an advisory sent to the Philippine Village Voice.

If you’re out in the heat and begin to feel dizzy, nauseated or thirsty; or if you develop a headache, stop and find a cooler place to sit down and drink some water.

Then, your heart has to pump even harder to get the smaller volume of blood distributed to your working muscles, skin and the other body parts. Extreme fluid loss can lead to brain and heart damage.

Plan your activities for the cooler part of the day such as early morning or late evening. Drink a cup of water before going out in the heat. People who are active for periods longer than 30 minutes should drink six to eight ounces of water (about a cup) every 10 to 15 minutes.

A good way to monitor your body fluid level is to weigh yourself every morning. If your weight is two or more pounds lower than usual in the morning, you may be dehydrated and need to drink more water before doing any vigorous physical activity. Remember, you may have lost weight as water, but not as fat.

The risk of dehydration increases when the humidity is above 70 percent and the temperature is greater than 70 degrees Fahrenheit.

It’s important to recognize the symptoms of heat exhaustion, which can quickly lead to heat stroke, a potentially fatal condition.