A Michigan police officer died and dozens of others needed medical care while running the Chicago Marathon on Sunday as record heat and smothering humidity forced race organisers to shut down the course midway through the event.

By 10 a.m., two hours into the race, the temperature had reached a race-record 88 degrees, but at least 12 of the Bermuda-based competitors in the event managed to complete the 26.2-mile route.

The previous record high for the race was 84 degrees in 1979.

The only Island runner who did not manage to finish was 70-year-old George Jones, a veteran of more than 30 marathons, who passed through the 25-kilometre (15.6-mile) mark in a time of three hours, 51 minutes, according to the Chicago marathon website.

Mark Albouy, one of the Island's top runners in the 50-plus age group, slowed dramatically in the latter stages. The 54-year-old reached the 35-kilometre mark in 3:01, but slowed to walking pace in the final 4.3 miles for a finishing time of 4:28:44.

Albouy's time was more than an hour slower than his performance on the same course in 2005 - a measure of how the heat took its toll.

Geoffrey Blee was the fastest Bermuda athlete, clocking a time of 3:14:06, while Dawn Richardson was the fastest Island-based female, finishing in 3:17:31.

The man who died was Chad Schieber, 35, who collapsed while running on the city's South Side and was pronounced dead shortly before 1 p.m. at a hospital, according to the Cook County Medical Examiner's office. An autopsy on the Midland, Michigan, man was scheduled for yesterday.

"Obviously very sad news, and our thoughts and prayers are with the individual's family," said Shawn Platt, senior vice-president of LaSalle Bank, the marathon's sponsors.

Schieber was a 12-year police veteran in Midland, a city of about 42,000 in central Lower Michigan. He worked as a field training officer and community relations officer and implemented the department's child DNA identification programme, the Midland Daily News reported.

About 10,000 of the 45,000 registered runners never even showed up for the 30th annual Chicago race, while another 10,934 started but didn't finish, officials said.

Measurements taken at Chicago's O'Hare Airport showed that relative humidity had reached 76 percent by 10.50 a.m. on Sunday and climbed further. The high heat index prompted organisers to stop the race at 11.30 a.m., about three-and-a-half hours into the race. Runners who hadn't reached the half-way point were diverted to the start and finish area, while those on the second half of the course were advised to drop out, walk or board cooling buses, Platt said.

Race director Carey Pinkowski said organisers were concerned that emergency medical personnel wouldn't be able to keep up with heat-related injuries as the weather turned more cruel.

"We were seeing a high rate of people that were struggling," Pinkowski said. "If you were out there at one o'clock, it was a hot sun. It was like a summer day, it was just a brutally hot day."

At least 49 people were taken to hospitals, while another 250 were treated on-site, many for heat-related ailments. Chicago Fire Department officials said they used 30 ambulances from area suburbs. Three people were in critical condition at Northwestern Memorial Hospital late on Sunday, according to spokeswoman Jennifer Monasteri.

Kenya's Patrick Ivuti won, leaning at the finish line to edge Jaouad Gharib of Morocco by 0.05 seconds. Ivuti, competing in only his second major marathon, was timed in two hours, 11 minutes, 11 seconds in the closest finish in the race's history. He was the fifth straight Kenyan to win the race.

Ethiopia's Berhane Adere rallied to successfully defend her women's title, finishing in 2:33:49 after passing a surprised Adriana Pirtea, who had a comfortable 30-second lead after 24.8 miles.

This newspaper was unable to contact any of the Bermuda contingent yesterday, but wire reports gave some runners' accounts.

Lori Kaufman, a runner from St. Louis, said she was told to start walking by mile 14. She said she didn't have enough water or Gatorade.

"We had a lot of spectators just handing us bottles of water which helped a lot," Kaufman said. "Every medic station that we passed was full of people. I mean they were not doing well."

Some kept going and helicopters hovered over the race course while police officers shouted through a bullhorn and warned runners to slow down and walk.

Fire hydrants were opened along the course and some residents who live along the race route used garden hoses to spray water on the weary runners.

Paul Gardiner, a runner from England, said the weather made for a "brutal" run.

"We were at about 18 miles and we heard they cancelled it and that kind of sent a little bit of concern through the crowd," Gardiner said. "It's just it was impossible to run."

Bermuda runners' times: Geoffrey Blee (3:14:06), Dawn Richardson (3:17:31), Calvin Steede (3:50:52), Troy Farnsworth (4:25:33), Mark Albouy (4:28:44), Jenene Douglas (4:50:55), Wendy Griffin (4:57:06), Terence Douglas (5:07:53), Clinton Curtis (5:39:25), Edwina Arorash (5:51:04), Julie Irvine (5:52:11), George Jones (did not finish).