This week's sudden onslaught of blistering heat shocked Twin Cities into summer, sending people to the hospital, crumbling roads and snarling traffic.

"We've had such a cold winter, and all of a sudden we're in the mid-90s," said National Weather Service meteorologist Jim Taggart. "It's a shock to the system."

Monday's high temperature of 97 degrees at Minneapolis-St. Paul International Airport broke the previous record of 95 set in 1987 and 1979. Another record is possible Tuesday, when temperatures could surpass the 95 degrees recorded in 2004. And with a dew point expected to be in the mid-60s, the temperature likely will feel like 100 degrees.

But relief from the heat is near with temperatures expected to dip back into the upper 60s by the end of the week and gradual warm-up likely into the 80s by next week.

Monday's heat sent at least six elderly patients and one firefighter to hospitals to be treated for heat exhaustion.

"These elderly people are usually dehydrated. They might have been out watering gardens, but are just not used to it. We expect to see more heat-related illnesses tomorrow," said Gloria O'Connell, a public relations manager at Allina Hospitals & Clinics.

Excessive heat warnings were issued for both Minneapolis and St. Paul downtowns, where all the concrete holds the heat and offers little relief at night, said Michelle Margraf, National Weather Service meteorologist. A heat advisory for the rest of the Twin Cities means people should take precautions: drink water, wear sunscreen, take frequent breaks from activity and watch for signs of heat illness.

"If you're more tired than normal, more winded and dizzy, stop and take a break," said Dr. Jerome Walker, chief resident of emergency medicine at Regions Hospital. A sports drink will help hydration, he said. "Prevention is the key."

The Office of Safety & Security and Emergency Management sent Minneapolis school district principals a memo to "encourage parents to dress their children appropriately for warm weather," including hats and sun protection. Nursing homes also issued similar recommendations. At the Birchwood Care Home in Minneapolis, a resident nurse said that extra water was brought to each of its 60 clients.

A staff physician at the Hennepin County Medical Center, Dr. Douglas Brunette, said that he treated a couple of heat-related cases last weekend but did not see any on Monday. He cautioned against young and elderly individuals from engaging in intense activities outside. "Most importantly, don't leave kids or pets in a car unattended for any amount of time even if you don't think it's a long time," Brunette said.

Monday's heat and humidity also took a toll on some area roads, buckling and crumbling a stretch of westbound Interstate 94 north of the Lowry Hill Tunnel. That shut down four of the five lanes, snarling traffic for hours during the afternoon and evening commute. Other heat-induced pavement failures created lane closures along Hwy. 100 and I-35W and on westbound I-94 near Hudson, Wis.

The summertime pavement blues come on the heels of a long winter that left commuters dodging potholes and a wet spring that flooded some roads.

"It just takes heat, humidity and the right amount of traffic volume to break up the pavement," said Todd Kramascz, spokesman for the Minnesota Department of Transportation.

The heat is causing newly planted gardens to droop, tormenting gardeners whose patience was tested during the cool, wet spring.

"For a long time, it was too wet and too cold to plant," said Deb Brown, former University of Minnesota horticulturist. "Now it's too hot."

Not even water can ease the pain on young plants.

"Now is not the time to be planting new plants," she said. "Even if you water, there's just not enough of a root system. ... For gardeners, this just has been so frustrating. It's just another crazy season."

tshamma@startribune.com • 612-673-7603 Twitter: @TasnimS mlsmith@startribune.com • 612-673-4788 Staff Writer Paul Walsh contributed to this report.