Evacuation orders are in alert for several B.C. communities Tuesday as the wildfire situation continues to intensify across the province.

The Dean River fire, burning 45 kilometres north of Bella Coola, on the province's Central Coast, forced evacuations Monday night from Kalone Creek to the Takla River.

The nearly 600 hectare blaze, started by lightning more than two weeks ago, also prompted the evacuation of two remote fishing villages along Dean River.

Evacuees are being told to register in Bella Coola, but that town is also cut off by a wildfire that severed Highway 20 through Tweedsmuir on Sunday.

Trucks with groceries and other supplies can't get through, leaving an estimated 2,000 people cut off.

A growing problem

The Bull Complex fire continues to grow near Alexis Creek, around 100 kilometres west of Williams Lake. The fire, which started July 28, now covers 24,000 hectares – or 240 square kilometres.

The largest of the B.C. wildfires is the Meldrum Creek fire, just west of Williams Lake, which registered a stunning 36,000 hectares late Monday night.

Almost 400 firefighters, aided by 14 helicopters and 53 pieces of heavy equipment, are working to conduct burn-off operations in hopes of reducing the tinder dry fuel at the fire's perimeter.

Provincial Fire Information Officer Alyson Couch says exhausted firefighters are being pushed to the limit.

"We are pretty much just holding our own right now," she said.

"Sometimes the (fire) behaviour is so extreme we have to pull our crews off in the afternoon. It's just not safe enough to be out there."

Air quality is plummeting across the province due to fine ash the fires are spewing into the air.

It's turned the Lower Mainland into a hazy mess and prompted warnings from Metro Vancouver on Monday.

Julie Saxton says people with health problems should stay inside and avoid strenuous activities outside for the time being.

"Those people who are sensitive, who have existing conditions, such as lung conditions, heart conditions, the elderly and very young people are certainly most at risk so be especially careful if you're caring for those people," Saxton told CTV News.

Air advisories are also in effect for the northern, central and east coast of Vancouver Island, as well as the Bulkley Valley & Lakes District.

Part of the haze in the air is also due to the extreme heat.

Eight temperature records were broken across B.C. Monday and another seven came within one degree of doing the same.

The heat wave has pushed the fire danger rating to critical levels. Three-quarters of the province is now at a high or extreme risk of fires.

Crews are hoping they can hold on just a few more days until the temperature is expected to cool.

"We are expecting a breakdown in the temperatures later in the week which means we might be able to get the upper hand," Couch said.

"So right now we're just holding our guards and hoping that the fires don't cross those guards."

There are currently more than 3,000 firefighters battling 260 wildfires burning in B.C.

A total of 1,434 fires have scorched more than 1,700 square kilometres since April. About 550 fires are said to be human caused. Roughly half are caused by lightning.

With a report from CTV British Columbia's Penny Daflos