A 60-year-old man from Toronto is missing after going ice fishing on Sunday.

York Region Police are searching the southern shores of Lake Simcoe, near Roches Point, where he was last seen. Authorities said they might expand their search to Cook's Bay.

"For people walking out on the ice right now, again, it's very unstable and simply put with the body weight, they could break through the ice and find themselves in the jackpot situation," York Region Police Const. Jeff Broughton told CTV Toronto.

An airboat and infrared technology are being used in the search but thick fog is hampering police efforts.

"Our visibility for the better part of the evening has been about 20 feet," Broughton said.

The man's vehicle has been retrieved.

The man has been identified as Ilia Vaxman. Police say he is a diabetic and is bi-polar.

Authorities are also warning the public about the dangers of thin ice.

Warmer temperatures have weakened ice rinks throughout the province and police say the public should steer clear of these areas.

"We're finding people walking along the shoreline, going out for a walk in the nice warm weather," said Darren Little, with the Toronto Police Marine Unit. "They see their pets go out on the ice. They think they can rescue them and they fall through."

Melting ice has also prompted the Conservation Authority to issue a high water warning.

Balmy weather

By 11 a.m., Toronto had set a new temperature record of 12 degrees Celsius.

But David Phillips, senior climatologist with Environment Canada, said people shouldn't get used to the balmy weather.

"Don't be lulled into thinking we've had winter and now spring is here," he told CTV Toronto.

He said we will not reach the record high - 17.6 C back in January, 2005.

Nonetheless, it was a pleasant surprise for people in the city.

"It's a great feeling," said one man, walking around the city without a jacket on. "I can't believe it's January and there's very little snow and very mild weather."

The average should be minus 1.8 C, but weather forecasters say freezing temperatures won't return until the weekend.

Forecasters are also predicting rain for the Greater Toronto area.

Ottawa's thaw is also causing authorities to warn people to stay away from the water there.

In eastern Ontario, about 5,000 students in the Belleville and Trenton areas got an extra day off school. Rain, fog and icy roads kept their school buses off the road.

The warm weather belt extends from Windsor in far southwestern Ontario, where a new record high was set, to Nova Scotia.

With a report from CTV Toronto's John Musselman