Sitting slumped under an umbrella on the sidewalk patio of Henry’s Coffee Shop, 11 E. Eighth St., Trisha Shrum was just trying to suck down her cigarette before heading back inside.

Across the street, a digital bank clock, basking all day in the sun, read 106 degrees.

“My roommate and I, we finally broke down and turned on the air conditioning,” the 23-year-old Lawrence resident said.

Finally? After three straight days of oppressive heat and sun, many Lawrence residents clicked on their A.C. units days ago, trying to avoid succumbing to what has been by far the hottest stretch of the young summer.

Temperatures reached 100 degrees Sunday with the heat index climbing as much as 15 degrees higher, said 6News forecaster Sarah Jones. A National Weather Service heat advisory remained in place throughout Sunday and into today.

The advisory expires at 7 p.m., the weather service said.

Sunday evening, even with the sun setting, temperatures still hung at 97 degrees, with a heat index of 112 degrees.

Nights in town haven’t been much better. The advisory warned that temperatures would fall only into the mid-to-upper 70s, with the heat of the day returning in a flash once the sun reappeared.

“With the humidity, it’s still going to be pretty hot and sticky,” Gordon Strassberg of the National Weather Service in Topeka said.

And the forecast doesn’t give the area much hope. National Weather Service forecasters said that the heat advisory likely would be extended throughout the week unless the humidity drops considerably between today and Tuesday.

The last few days of heat has resulted in at least seven heat-related medical problems for Douglas County residents, fire and medical officials say, and likely more that were called in as other problems, such as cramping or shortness of breath.

“It’s pretty hard on people,” Lawrence-Douglas County Fire & Medical Battalion Chief Jerry Karr said. “We know trends; we know what to expect.”

Karr said he expected more heat-related calls this week, including more health problems, grass fires and people without power because of troubles on the electric grid.

Two power outages have hit the area since Friday, Westar spokeswoman Cynthia McCarvel said. On Friday afternoon, a transformer shut down in De Soto, cutting power to about 1,300 homes for most of the day.

Then, Saturday morning, underground equipment near 15th and Iowa streets went on the fritz, cutting power to homes and parts of the Kansas University campus. That outage affected about 6,000 people, McCarvel said, but power was back on by Saturday night.

McCarvel wouldn’t say that the outages were directly related to the heat but admitted that the steamy weather isn’t great for electrical equipment.

“With the extra heat like this, it puts a strain on everything,” McCarvel said.

The weekend’s heat may seem out of the ordinary, but Strassberg said that in general, this heat wave isn’t unusual for this time of year – even though temps are about 10 degrees above average.

“This is typically our warmest period of the summer,” Strassberg said.

Even so, he said, the area hasn’t officially surpassed 100 degrees since August 2003 and may not again in the near future. 6News reported that the temperature last reached 100 degrees July 25, 2005.

“But when it’s this hot and humid, it doesn’t make much of a difference,” Strassberg said.

Back at Henry’s, Mickey Cesar sat with Shrum sipping an iced coffee. For Cesar – a tall, thin fellow – the heat is merely an inconvenience for his cat.

So just a few days ago, Cesar cranked back up the air conditioning to keep his feline feeling well as the rest of Lawrence swelters.

“Otherwise,” Cesar said, “I’d go without.”