Chicago was so hot on Friday it set a record — but not the one you might be thinking of.

The city didn’t break the record high temperature for July 19. That was 101 degrees, set in 1930 — and the city peaked at 93 degrees Friday at O’Hare.

But the city did set another record — for the highest recorded low temperature for July 19.

The temperature Friday never dropped below 81 degrees, according to the National Weather Service. The previous “highest low” was 78 degrees, set in 2011.

So, when midnight passed with the temperature at 86 degrees, a new record for July 19 had been set.

The Chicago area has been under an excessive heat warning since Friday morning, and authorities have warned residents to be cautious as the life-threatening temperatures remain until a cool front moves in Sunday morning.

“The best thing to do is stay out of the heat as much as possible,” National Weather Service Meteorologist Casey Sullivan said. “You want to limit your activities outdoors. If you are outside, take breaks.”

The city operates six cooling centers, and people are urged to call 311 to request a well-being check on someone who may be suffering from the heat.

“People just need to take it easy until that cool front moves through Saturday night into Sunday morning,” Sullivan said.

Saturday is expected to be dangerously hot as well, topping off at 94 degrees. But we are unlikely to beat any records Saturday, either. The record high for July 20 is 101 degrees, set in 1980.

The continuing heat forced the cancellation of one out of three races in the Humana Rock ‘n’ Roll Marathon series. Saturday’s 5K race, set to begin at 7:30 a.m. in Grant Park, was called off.

But with cooler temperatures forecast for Sunday, that day’s 10K and half-marathon are still on.