Canada's government has warned of a "long and challenging summer" ahead as it prepared military aircraft to help evacuate towns and fight more than 100 wildfires fueled by a record-breaking heat wave.

At least 152 fires were active in the western province of British Columbia, 89 of them sparked in the last two days, according to officials. Most were caused by lightning strikes.

The fires were north of the city of Kamloops, 350 kilometers northeast of Vancouver.

While the immediate blame for the scorching heat in Canada has been placed on a high-pressure "heat dome" trapping warm air in the region, climate change is causing record-setting temperatures to become more frequent.

Globally, the decade to 2019 was the hottest recorded, and the five hottest years on record have all occurred within the last five years.

"The dry conditions and the extreme heat in British Columbia are unprecedented," Public Safety Minister Bill Blair said yesterday. "These wildfires show that we are in the earliest stages of what promises to be a long and challenging summer."

Yesterday, Prime Minister Justin Trudeau met with an incident response group that included several ministers. He said he had already spoken with British Columbia's premier, as well as local mayors and indigenous chiefs in communities under threat.

"We will be there to help," he told a news conference.

The response group announced it would set up an operations centre in Edmonton, where armed forces will be able to provide logistical support.

Military aircraft were also deployed to help.

Roughly 1,000 people have already fled the wildfires in British Columbia, and authorities are searching for many who have gone missing.

The British Columbia medical examiner's office said there had been 719 deaths in the past week, "three times more" than the average number of deaths recorded over this period under normal circumstances.

"It is believed likely the extreme weather BC has experienced in the past week is a significant contributing factor to the increased number of deaths," Lisa Lapointe, the province's chief coroner, said in a statement.

The village of Lytton, 250 kilometers northeast of Vancouver, was evacuated Wednesday night because of a fire that flared up suddenly and spread quickly. Nearly 90% of the village was torched, according to Brad Vis, an MP for the area.

The fire came a day after the village set a Canadian record-high temperature on Tuesday of 49.6C.

"I cannot stress enough how extreme the fire risk is at this time in almost every part of British Columbia and I urge British Columbians to listen carefully to officials in your communities and follow those directions," provincial premier John Horgan said.

The heat wave continued to spread across central Canada yesterday. In addition to British Columbia, heat wave warnings were issued for the provinces of Alberta, Saskatchewan and Manitoba, as well as parts of the Northwest Territories and northern Ontario.