(CNN) - Twenty-nine children across the U.S. have died due to heat stroke after being left in a hot car this year. That's a record high.
Extreme heat is defined by the CDC as temperatures that are significantly hotter and more humid than average
When a person's body temperature rises too much, there can be damage to the brain or other vital organs.
This is a real risk during the summer, especially in extreme heat. So it's important to know the signs of heat-related illness.
Heat-related illnesses, like heat exhaustion or heat stroke, can happen when the body is not able to properly cool itself.
Older adults, people with mental illnesses or chronic diseases, and the very young are most likely to be affected by heat-related illnesses.
Signs of heat exhaustion include heavy sweating; headache; nausea or vomiting; muscle cramps; feeling weak or dizzy or passing out.
If you are experiencing these symptoms, move to a cool place, sip water and loosen your clothes.
Try putting cool, wet cloths on your body or taking a cool bath.
Get medical help if you throw up, or if your symptoms worsen or last longer than an hour.
If, in addition to the symptoms of heat exhaustion, you have a feeling of confusion and a high body temperature - 103 degrees or higher - you may be having a heat stroke.
People experiencing heat stroke should not drink water. That's a medical emergency and you should call 911 right away.
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