SHARECOMMENTMORE

GRAND RAPIDS (WZZM) -- Michigan's early-July heat wave pushed up hospital emergency department visits for heat illness by 89% from the previous ten-day period.

Figures compiled by the Michigan Department of Community Health show 734emergency departmentvisits were reported --versus 389 for the previous period.

Spectrum Health's Grand Rapids-area hospitals had three cases of the most serious heat stroke, which can be fatal. Saint Mary's Health Care recorded one case of heat stroke. Metro Health'semergency departmentwas busy as well.

Doctors at these hospitals note that people who are very young or very hold are most susceptible to heat illness and exhaustion. Symptoms include weakness, headache, nausea and vomiting. People on multiple medications are at special risk since the drugs can blunt thirst or decrease sweating.

The treatment? Get to a cool place and drink plenty of fluids.