CHICAGO (STMW) — The week will start out a scorcher and then maybe — maybe — ease up by Labor Day weekend, according to the National Weather Service.

“Today will probably be the coolest of the next several days,” said meteorologist David Beacher Sunday from his office in Romeoville.

Monday — when some 400,000 Chicago Public School students start classes — will hit the low 90s, and Tuesday mid-90s, which is hot but doesn’t break a 1973 record of 97 degrees. The heat is sliding toward Chicago from the southwestern states.

It’s the heat index that’ll be killer, Beacher said. Moisture in the air will make both days feel more miserable, with Tuesday’s heat index potentially hovering around 100.

And if there are any clouds Monday night, Tuesday weather at sunrise will start out even hotter and build from there.

“A few locations could flirt with record highs as we get into Tuesday,” he said.

Wednesday will be cooler, with a high around 77 degrees, according to the weather service. But the mercury is expected to be on the rise again.

Despite a heater of a week, August had some cool patches in its first and second weeks, so overall, the average temperatures have been pretty normal, Beacher said.

People should start drinking lots of water now, he said.

“They need to prepare for it and need to prepare today,” Beacher said.

In addition to drinking plenty of water, experts suggest wearing loose-fitting clothes and scheduling activities for early morning or after sunset.

While the Chicago area could see a high of 90 degrees — or close — that didn’t put the brakes on Sunday’s annual triathlon.

A little wind made for a “head breeze” for bikers, event spokesman Scott Hutmacher said.

And the Chicago Fire Department provided a 30-foot wide “rainmaker” to sprinkle water on the estimated 7,000 athletes racing Sunday in the 31st annual Life Time Chicago triathlon.

But the temperature in Lake Michigan was about 72 degrees Sunday morning — or “incredibly comfortable,” for the swimming portion of the triathlon, Hutmacher said, adding, “It is not too hot, not too cold.”

The non professional athletes — or “average Joes” swam, biked and ran from 6 a.m. to 2 p.m., with 51 registered professional athletes starting at 11:15 a.m., he said.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2013. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

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