
Health officials are offering safety tips and cooling centers have been opened as peak heat index values of up to 115 degrees are expected in the Chicagoland area Tuesday.
The National Weather Service (NWS) issued an excessive heat warning Tuesday morning.
The warning covers the Winnebago, Boone, McHenry, Lake, Ogle, Lee, Cook, DeKalb, Kane, DuPage, La Salle, Kendall, Grundy, Livingston, Iroquois, Ford and Will counties.
The warning will remain in effect until 10 p.m. Tuesday.
The NWS said dangerously hot conditions with heat index values of 110 to 115 degrees are expected on Tuesday, with the hottest temperatures being seen from 12 p.m. to 10 p.m.
Extreme heat and humidity will significantly increase the potential for heat-related illnesses, especially for those working or participating in outdoor activities, the NWS said.
The NWS said people should also be prepared to drink lots of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors.
Young children and pets should never be left unattended in vehicles under any circumstances, the NWS said. “This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.”
Extreme heat can lead to heat stroke, heat cramps, heat exhaustion, dehydration, and death, according to the CDC.
Groups that are more vulnerable to the heat are pregnant women, people with heart or lung conditions, young children, older adults, athletes and outdoor workers.
The McHenry County Department of Health and McHenry County Emergency Management Agency said residents should stay hydrated, limit outdoor activities, check on vulnerable individuals, know the signs of heat-related illness, ensure pets are safe and visit a cooling center if access to air conditioning is not available.
McHenry County has numerous cooling centers that can be found here. Lake County also operates numerous cooling centers that can be found here.
Woodstock School District 200 said several of its schools will dismiss early on Tuesday due to the heat. School was canceled for pre-K students.
The NWS said there is a chance 40-50% chance of scattered strong to severe thunderstorms from late afternoon into Tuesday evening.
Damaging winds are the primary threat and isolated large hail is also possible. Storms may produce locally heavy rainfall with the potential for localized flooding.