The Centers for Disease Control and Prevention list the following signs of heat stroke: body temperature higher than 103 degrees Fahrenheit (39.4 degrees Celsius); hot, red, dry, or damp skin; headache, dizziness, nausea, and confusion; a fast, strong pulse; and loss of consciousness. If you think you or someone else is experiencing heat stroke, call emergency services and move to a cooler place. Do not give them anything to drink.

Centers for Disease Control and Prevention, July 2019