LINCOLN -- After a July with no 90-degree days, the weather service is reminding Central Illinoisans just how dangerous extreme heat can be.

The high in the Twin Cities is expected to hit 92 degrees Saturday and 93 degrees Sunday. A heat advisory is in effect from 1 p.m. Saturday until Sunday night for much of Central Illinois.

Heat index values on both days are expected to range from 100 to 105 degrees, the National Weather Service's Lincoln office reported.

Many parts of Central Illinois haven't seen weather this hot in awhile.

"As people may no longer be used to the summer heat, there is a potential for overexertion and resulting heat-related illnesses," the NWS warned.

Officials at the American Red Cross say the very young and elderly are at the greatest risk for heat-related illnesses like heat stroke or heat exhaustion.

Red Cross health expert Joel Schilling said symptoms include nausea, dizziness, flushed or pale skin, heavy sweating and headaches. He advises those suffering from the symptoms "be moved to a cool place, given cool water to drink and ice packs or cool wet cloths should be applied to the skin."

The Red Cross also advises avoiding strenuous activity, slowing down and staying indoors. They also recommend wearing light clothing and drinking water.

Things are expected to cool off ever so slightly Monday, with a high of 90 degrees forecast for the Twin Cities. The NWS says clouds and an increasing threat for rain will likely usher in slightly cooler weather.