Answer:
-At or greater than 104.0 °F.
Explanation:
Heat stroke or sun stroke can be defined as a severe heat illness, when internal body temperature reaches to (or above than) 104.0 °F. Symptoms include confusion, headache, dry or red skin, and dizziness.
The main cause for heat stroke is overwhelming of thermoregulation due to excessive environmental heat, excessive exertion (heat production due to metabolic activity), or insufficient heat loss.
Thus, the correct answer is '104.0 °F.'
