High body temperature
If your body temperature hits 103 degrees Fahrenheit or higher, you could be dealing with heat stroke, according to the CDC. If you take someone’s temperature and it’s lower than that-but they still exhibit other heat stroke symptoms or feel that something is wrong-you should still do what you can to cool them down and get medical help.
A lack of sweat-or an abundance of it
When you spend a long time in extreme heat, the body stops trying to maintain its core internal temperature. So, during traditional heat stroke (remember, that’s the kind that comes on gradually), you may actually stop sweating. However, you’ll probably start sweating like crazy if you’re experiencing exertional heat stroke.