All of northern Illinois is under a heat advisory and an air quality alert today, June 28.
The National Weather Service issued the heat advisory because temperatures are expected to reach between 100 and 105 degrees, with a heat index between 105 and 110 degrees.
"Prolonged exposure to this heat can be dangerous if the proper precautions are not taken," according to the National Weather Service's Chicago office. "Sunstroke, heat cramps or heat exhaustion are possible with prolonged exposure and physical activity."
The National Weather Service advises that people should wear lightweight and loose-fitting clothing, and drink plenty of water.
The heat advisory will be in effect from noon to 8 p.m.
It is also an air pollution action day, according to the Illinois Environmental Protection Agency and Partners for Clean Air. The air pollution action day includes Cook, DuPage, Grundy, Kane, Kendall, Lake, McHenry and Will Counties.
"Ground-level ozone levels are elevated, posing a potential health risk to sensitive populations, especially individuals with respiratory or pulmonary disorders as well as active children and adults," according to the EPA. "Those individuals should take special precautions and follow their physician prescribed regimen. Residents should keep cool and limit physical activity when air pollution levels are high."