Excessive Heat Warning in effect for Northern Illinois, dangerous temperatures possible

An excessive heat warning has been put in place Wednesday and Thursday for Northern Illinois with meteorologists concerned heat indexes could reach as hot as 115 degrees.

A heat advisory has been issued from 11 a.m. to 9 p.m. Wednesday for Ogle, Lee, DeKalb, Kane, La Salle, Kendall, Grundy, Putnam, Bureau, Livingston and Will counties. An excessive heat watch remains in effect from 9 p.m. Wednesday through 8 p.m. Thursday.

“When we see heat indexes in the 110 to 115 range, that’s dangerous for anyone outdoors.”

—  Zachary Yack, meteorologist with the National Weather Service

A heat advisory indicates heat indexes could reach 105 degrees or hotter, but forecasters believe heat indexes may exceed 110 degrees Wednesday and Thursday, which resulted in the Excessive Heat Warning, the most extreme hot weather warning at the National Weather Service’s disposal.

The forecast on Tuesday calls for high temperatures between 88 and 93 degrees and heat indexes of 95 to 105 degrees. The heat index measures temperature and humidity to indicate what it feels like.

High temperatures are predicted to be 95 to 98 degrees on Wednesday and 97 to 99 degrees on Thursday with heat indexes possibly reaching 115 degrees. Low temperatures also will stay in the high 70s overnight, meaning there won’t be a substantial cool off.

“When we see heat indexes in the 110 to 115 range, that’s dangerous for anyone outdoors,” said Zachary Yack, a meteorologist at the National Weather Service in Romeoville. “Anyone who works outdoors should monitor the forecast and make alternative plans, so they spend less time outside and avoid the hottest parts of the day, which is 2 to 4 p.m.”

An excessive heat watch is put into place when there is a 50% chance or more of 110 to 115 degree heat indexes.

Yack said the watch has not been elevated to a warning just yet, because meteorologists are watching a shower and storm system over northern Wisconsin and Lake Michigan that could push outflow from the lake. If these showers or storms occur, it could cool down lakeshore communities and if the system is strong enough, produce more outflow farther inland. The system also may cause some cloud debris and cool temperatures down a little.

Residents should take precautions.

The American Red Cross offers the following tips to stay safe during the heat wave:

Hot cars can be deadly. Never leave children or pets in your vehicle. The inside temperature of the car can quickly reach 120 degrees.

Stay hydrated by drinking plenty of fluids. Avoid drinks with caffeine or alcohol.

Check on family, friends and neighbors who do not have air conditioning, who spend much of their time alone or who are more likely to be affected by the heat.

If you don’t have air conditioning, seek relief from the heat during the warmest part of the day in places like schools, libraries, theaters, malls, etc.

Avoid extreme temperature changes.

Wear loose-fitting, lightweight, light-colored clothing. Avoid dark colors because they absorb the sun’s rays.

Slow down, stay indoors and avoid strenuous exercise during the hottest part of the day.

Postpone outdoor games and activities.

Take frequent breaks and use a buddy system when working outdoors.

Check on animals frequently to ensure that they are not suffering from the heat. Make sure they have plenty of cool water and shade.

Excessive heat can lead to sunburn, heat cramps, heat exhaustion and heat stroke.

Individuals should take extra precautions if they work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Anyone overcome by heat should be moved to a cool and shaded location. Call 911 if they are experiencing heat stroke.

“With dangerously high temperatures and humidity in the forecast, I urge everyone to take precautions and protect themselves and their families from overheating and heat related illnesses,” said Illinois Department of Public Health Director Dr. Sameer Vohra in a news release. “This is especially important for very young children, people who are pregnant and those who are older or have chronic health conditions.”

Symptoms of heat stroke

Throbbing headache, confusion, nausea, dizziness, body temperature hotter than 103 degrees, hot, red, dry or damp skin, rapid and strong pulse, fainting and/or loss of consciousness (source National Weather Service)

First aid for heat stroke

Call 911 or get the victim to a hospital immediately, according to National Weather Service. Heat stroke is a severe medical emergency. Delay can be fatal. Move the victim to a cooler, preferably air-conditioned, environment. Reduce body temperature with cool cloths or bath. Use fan if heat index temperatures are cooler than the high 90s. A fan can make someone hotter at higher temperatures. Do not give fluids at this point.