A stifling heat wave blanketed Iowa City on Monday, causing residents to shed warm clothing and seek shaded areas.

Air temperature escalated to 98 degrees, and humidity pushed the heat index up to a scorching 105. And, said David Sheets, a meteorologist with the National Weather Service in the Quad Cities, local residents can expect these temperatures to persist into late Thursday.

"We’re not quite into record high temperatures for the week, but it’s close," he said. "It will be quite hot in the following days, so use your air conditioners. Stay home. Drink a lot of water."

Some locals, however, are choosing not to heed his advice.

Blake Stephens, a 27-year-old Iowa City restaurant worker, jogged along the Pentacrest Monday, his gray University of Iowa shirt drenched with perspiration.

"It’s insanely hot today, but you can’t let that keep you inside," he said. "Before you know it, there will be snow on the ground."

Attached to his back was a 20-pound hiking backpack filled with water. Stephens removed the bag, hefting it up and down.

"You’d be a fool to run in this weather without a ton of water," he said, wiping his forehead with a cloth.

Patricia Quinlisk, the medical director of the Iowa Department of Public Health, said heat exhaustion can occur suddenly, and there are a few things people can do to avoid health problems.

"Stay inside," she said. "If you have to go outside, try to do so during the morning or evening. And I know a lot of people laugh at this, but check your urine. The darker yellow it is, the more water you should be drinking."

Quinlisk also warned against leaving any children or animals in vehicles, saying cars and trucks can become "miniature furnaces."

"Very young children are already at a higher risk for heat illnesses because they aren’t as aware of dehydration and sometimes can’t get or communicate that they need water," Quinlisk said. "Animals also can’t tell you when they’re thirsty, either, so it’s best not to leave them in a vehicle — even for a short time."

Rick Dobyns, a UI clinical professor of family medicine, said he’s seen a substantial increase in heat-related emergency incidents this week, though he couldn’t comment on the number. The emergency room is preparing for more patients by ensuring cooling blankets and IV fluids are plentiful.

Dobyns said people — especially older individuals — should seek shelter and water if they suffer problems with breathing, nausea, dizziness, quick pulse, or rashes.

"When you grow older, your sense of thirst dulls," Dobyns said. "Then there are several common medications that elderly people take that further decrease that awareness. If you have an elderly neighbors, it might not be a bad idea to check up on them."

But above all other symptoms, Dobyns said, a body that no longer produces sweat is in need of immediate medical attention.

"When your core temperature exceeds 104 degrees, you’re in heat-stroke range," he said. "You may stop sweating, and sweating is how your body cools itself. It’s best to not let yourself reach this point."

Sheets said today’s heat index is expected to hit more than 100 degrees.