Almost 100 forest fires are burning in northwestern Ontario, forcing more than 1,000 First Nations people from their homes and sending smoke as far away as Newfoundland and Labrador.
More than 30 new blazes are expected to break out in the coming days as the fires spread southward.
Mitch Miller, a fire information officer with the Ministry of Natural Resources, said from Dryden that there are 96 active fires burning in the remote northwestern region.
"We have got increasingly hot weather, we're getting drier conditions and we've had lightning strikes just about every day," he said.
The fires so far have threatened some First Nations communities and changes in the wind will raise new challenges, he said.
"We've got firefighters and water bombers and helicopters working on fires from Kenora over towards Nipigon and all the way north and what we're seeing is increasing fire activity moving to the south."
Hydro lines, highways, cabins, and people working in the forest industry will be at more risk as the fires move south, he said.
More than 2,000 staff are being helped by another 500 reinforcements from B.C.
Miller said firefighters are dressed in fire-retardant clothing including long sleeves and pants and carrying 25-kilogram packs, so they have to be careful to avoid heat stroke by drinking enough fluids.
"It's very hot and very strenuous but they're doing an excellent job," he said.
Many northwestern communities are dealing with smoke issues and are planning for evacuations with federal and provincial authorities. "It's a real dynamic situation and it doesn't look like it's going to change any time soon," Miller said.
At least four fires are also burning in northeastern Ontario — one near Timmins and three near Cochrane.
Smoke from the province is spreading as far as Newfoundland and Labrador and into New Brunswick. CBC meteorologist Johanna Wagstaffe says the wind is expected to shift periodically over the next few days, which could push smoke further south into Winnipeg, Thunder Bay, Ont., and Kenora, Ont.