Updated 7/5/2012 at 5:45 p.m.

CHICAGO (CBS)–Summer classes at Chicago Public Schools buildings have been canceled Friday for students and teachers because of the heat, officials said.

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CPS Supt. Jean-Claude Brizard cited continuing high temperatures, which are expected to hit more than 100 degrees Friday.

“Due to reports of the excessive heat that will continue throughout Chicago again tomorrow, we have determined that it is in the best interest of our students and instructional staff to cancel summer school for all CPS sponsored sites tomorrow,” Brizard said in a written statement.

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School administrators and engineers are expected to report to all sites Friday, CPS said in a news release.

CPS earlier had canceled Thursday classes at 21 CPS buildings that have no air conditioning, also due to the extreme heat.

CBS 2 Meteorologist Ed Curran says the high for Thursday is expected to hit 103 degrees, and an excessive heat warning remains in effect all the way up through 10 p.m. Friday.

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CPS will monitor the heat and provide additional information through its Web site as well as Facebook and Twitter.