Chicago Public Schools CEO Jean-Claude Brizard has canceled summer classes Thursday at 17 schools without air conditioning because of soaring temperatures that could top 100 degrees.

“Due to reports of excessive heat throughout Chicago tomorrow, we have determined that it is in the best interest of our students and instructional staff to cancel summer school for the day in non-air conditioned buildings,” Brizard said in a release issued late Wednesday.

Schools that will be closed on Thursday include Altgeld, Attucks, Bennett, Brentano, Faraday, Gregory, Hedges, Holden, Jahn, Kenwood, Manierre, Mayo, Penn, Pierce, Pope, Stevenson and Harold Washington, the release said.

Forecasters predict temperatures could reach 100 to 105 degrees both Thursday and Friday, according to the National Weather Service. Combined with high humidity, the heat index -- a measure of what it actually feels like outside -- could creep as high as 108 to 118 degrees, the weather service warns.

CPS officials will continue to monitor the heat wave, and urge parents to monitor any other announcements on the CPS website or their local news.

Meanwhile, an excessive heat warning remains in place for the entire Chicago area through 10 p.m. Friday, according to the weather service, and officials urge residents to avoid strenuous activity outside, drink lots of water and check on relatives and neighbors.

An air quality alert is also in place through Thursday for elevated ozone and particulate levels that will especially impact the very young and elderly, according to the Illinois Environmental Protection Agency.