Heat advisory for Chicago area starts today; humidity adds to dangerous temperatures

CBS News

5 days ago

A Heat Advisory is in effect for the entire Chicago area Wednesday, lasting through Thursday night, as high temps and humidity combine to make a heat index well into the triple digits.
While actual temperatures today and tomorrow are in the mid- to high-90s, the humidity will make it feel like anywhere from 105 to 115 degrees.
The humidity is driven at least in part by what's commonly called "corn sweat," an agricultural phenomenon formally called transpiration in which plants release water from their leaves to help them move water. Corn, soybeans, alfalfa and sugarcane are crops with high levels of transpiration, which releases more moisture into the air; Illinois leads the country in corn growth with about 11 million acres planted.
The Heat Advisory was issued for Boone, Cook, DeKalb, DuPage, Lake, Will, Kane, Kankakee, LaSalle, Kendall and McHenry counties in Illinois and Benton, Jasper, Lake, Newton and Porter counties in Indiana until 10 p.m. Thursday night.
In such extreme heat, anyone going outside should make sure they drink water before leaving the house and continue to drink water as often as possible while outside. Doctors recommend drinking water every 20 minutes if possible.
It's also advisable to wear light-colored clothing which reflects the sun instead of absorbing heat.
Cooling centers are open in Chicago and Cook County to help people who don't have air conditioning or access to reliable air conditioning, and officials are asking residents to make sure they check on their elderly or health compromised neighbors to ensure they're staying safe in the dangerous temperatures.
All Chicago public pools are also open, most from 11 a.m. to 7 p.m., as are city splashpads and water features in parks.
Still, in such extreme heat and humidity, experts recommend staying inside as much as possible, and seeking shade when you do leave the house.
Heat exhaustion and heatstroke are major risks during these weather events, especially with high humidity. It is easy to become overheated and dehydrated in high temperatures, so it is essential to make sure you are drinking enough water.
Heat exhaustion is milder than heat stroke. Heatstroke is a serious illness that happens when the body begins to lose its ability to regulate its own temperature and functions, and can result in permanent disability or death if not treated as quickly as possible.
Heat exhaustion symptoms include headache, nausea, dizziness, weakness, irritability, thirst, heavy sweating, high body temperature and decreased urine output.
If you or someone you know is experiencing heat exhaustion move into a cool indoor space or shade immediately, give them liquids to drink, remove unnecessary clothing including shoes and socks, used cold water or a cold compress to cool the person down on their head, face and neck, and frequently sip cold water. The CDC also encourages calling 911 or taking the person to an urgent care clinic or the emergency room for treatment.
Heatstroke symptoms include confusion, altered mental status, slurred speech, hot and dry skin or profuse sweating, very high body temperature, loss of consciousness, and very high body temperature. If treatment is delayed, it can quickly become fatal, the CDC says.
If you are with someone experiencing heat stroke, call 911 immediately and stay with that person until help arrives. Move them into a shaded, cool area and remove their outer clothing then work to cool them down as quickly as you can with cold water or an ice bath if possible. Wet the skin or place cold, wet clothes on the skin, or soak their clothing with cold water. You should also circulate the air around them by fanning to help cool them off. The CDC also recommends placing cold wet cloth or ice on the head, neck, armpits and groin to help cool them faster.