Dr. Sanjay Gupta: Watch for warning signs of heatstroke

CNN Medical Correspondent Dr. Sanjay Gupta

(CNN) -- CNN Medical Correspondent Dr. Sanjay Gupta explains the symptoms of heat exhaustion and heatstroke -- and tells you what to do if you develop them.

This week we're facing the hottest temperatures of the summer so far and it's important for you to know the warning signs of heat exhaustion and heatstroke.

Heat exhaustion is the first stage of illness due to over exposure to the sun.

Symptoms include: heavy sweating, muscle cramps, weakness, headache, nausea or vomiting and dizziness or fainting. If you notice these symptoms early, they can usually be handled by drinking a cold, non-alcoholic drink, getting out of the heat, resting, taking a cool shower or wiping yourself with a wet towel.

But if heat exhaustion goes untreated, it may lead to a life threatening condition called heatstroke.

Symptoms include: a very high body temperature, rapid pulse, confusion and unconsciousness.

If you find someone with heatstroke symptoms, instruct another person to call 911 while you get the sufferer into air conditioning, or at least a shaded area. Cool down their body by spraying with or immersing in cool water. Only give the victim fluids if he is conscious and not vomiting.

It's critical to treat heatstroke quickly and effectively as it can spiral out of control.

Of course your best bet to stay out of danger from the heat is to play it safe. Pay attention to signals from your body, keep drinking liquids even if you are not thirsty, and don't push yourself too hard. Whenever possible, stay out of the heat.