The National Weather Service has issued a heat advisory for central Wisconsin effective at noon Friday and extending through 4 p.m. on Saturday, with temperatures rising into the mid-90s and heat indices topping 100 degrees.

Heat advisories are issued when hot temperatures and high humidity combine to create situations where heat illnesses are possible, especially impacting the elderly and people who work outdoors. The Marathon County Public Library’s locations are designated cooling centers for people who do not have air conditioning in their homes.

Residents should drink plenty of fluids, stay in an air conditioned room and out of the sun, and be sure to check up on relatives and neighbors, according to the NWS. People who work or spend time outside should take extra precautions or reschedule strenuous activities to early morning or evening.

Health officials say knowing the signs and symptoms of heat exhaustion and heat stroke is imperative when scorching temperatures are expected.

According to the Department of Health Services, 39 people have died in Wisconsin over the last five years and thousands of residents have fallen ill or even been hospitalized due to heat-related conditions. Nationwide there are an average of 618 deaths in the U.S. each year caused by extreme heat, according to the Centers for Disease Control and Prevention.

State health officials say keeping shades drawn and blinds closed, but windows slightly open, is a good idea for people who do not have air conditioning. Limit the use of the stove, keep electric lights off or turned down, and rotate ceiling fans counter clockwise to help beat the heat. Be sure not to leave anyone — including pets — in a parked car, even for a few minutes. And it’s a good idea to check up on family, friends and neighbors during periods of extreme heat. If you are unable to reach them, call 911 and request a well-being check.