High Body Temperature
A body temperature of 104 degrees or higher is the primary symptom of heat stroke, though some people may not realize their body temperature has climbed to such levels.
Another early indication that your body temperature is too high is if you have been sweating and suddenly the sweating ceases. When heat stroke results from exposure to hot weather, the skin itself will become dry and hot to the touch. When strenuous exercise is the cause, the skin will feel moist. But in both cases, sweat will not be evident. The skin may appear red and flushed.
People who have heat stroke may experience quick and shallow breathing--hyperventilation--and may have difficult breathing.
Increased Pulse and Heart Rate
The normal pulse rate for adults is 60 to 100 beats per minute, according to the Mayo Clinic. People experiencing heat stroke may have a pulse of 130 beats per minute or more. This occurs because the heat causes your heart to beat faster as it works to cool your body.
Some of the neurological symptoms of heart stroke include a loss of consciousness, confusion, agitation, seizures or hallucinations. Sufferers also may have a hard time talking or understanding what other people are saying.
The presence of muscle cramps or a general feeling of weakness are signs of the onset of heat stroke. During the early stages, muscles may feel tender or cramped, but as heat stroke progresses, muscles may become rigid or limp.
Like a Heart Attack
Some people experiencing the symptoms of heat stroke actually believe they are having a heart attack because some of the symptoms--nausea, vomiting and dizziness, for example--are the same or similar.