According to WebMD, the trademark sign of a heat stroke is an elevated core body temperature over 105 degrees Fahrenheit. Other symptoms may include a pounding headache, lack of perspiration, muscle weakness, dizziness, feeling light-headed, seizures, unconsciousness, rapid heartbeat and breathing or disorientation.
According to WebMD, heat stroke is more likely to occur with older individuals in environments lacking air conditioning or sufficient airflow. Other groups that have an elevated risk of heat stroke including people of any age lacking sufficient water, those with chronic diseases and people who consume great amounts of alcohol. A person suspected of having heat stroke requires immediate medical attention.