The platoon commander shouts the warning to about 200 soldiers slogging their way through the dense brush, blackened trees and smouldering ash in the tiny First Nations community of Montreal Lake, about 250 kilometres north of Saskatoon.
A widowmaker is any large branch or treetop no longer attached to a trunk, but still tangled overhead, that could fall at any time.
"Obviously there's the danger of the ash pits and the big concern right now is the burned-out trees — any widowmakers," says Master Cpl. Casey Zaharoff. "And obviously a flare-up."
Casey is one of the hundreds of Canadian Forces personnel who have traded their camouflage duds for bright-orange fire-fighting jumpsuits to help beat back the flames in an unprecedented fire season.
For soldiers in northern Saskatchewan, for now, orange is the new green.
A handful of homes and cabins in the area have already been destroyed by fires. The army was called in this week to help save the rest and get 10,000 people who have fled the smoke and flames back home.
The help is sorely needed.
Crews were holding protective lines around threatened communities Thursday, but Steve Roberts with Saskatchewan Wildfire Management said warm, dry conditions and shifting winds could cause more trouble spots.
The narrow dirt road into Montreal Lake is flanked by burned trees, many of them still smoking.
The community is deserted. Several stray dogs follow along behind the soldiers.
It's dry, smoky, hot work. The temperature was forecast to rise over 30 C on Thursday.
The soldiers push through the bush in long lines and climb over downed trees to get to ones that are still smoking or to hotspots on the ground.
There is nothing high-tech in what they are doing. The main tools are shovels, axes and hand-held water sprayers fed by plastic bladders on their backs.
It's challenging, says commanding officer Lt.-Col. Mason Stalker.
"Certainly fatigue and, of course, the heat are some of the threats that our soldiers deal with," he said. "Of course they're wearing protective equipment, goggles, hard hats, coveralls and gloves."
Stalker said there are about 200 soldiers in Montreal Lake and another group about the same size in La Ronge, the largest community under threat. He expects another 60 reservists from Saskatchewan will join the fight on the weekend.
Roberts said the province is looking for more firefighters and equipment from across the country and the United States. It is also working to train hundreds of additional people to join the battle in the next few weeks.
Saskatchewan used to have a larger force of firefighters, but there hasn't been a bad wildfire season for years and some moved on to take jobs in the energy industry, he said.
"Now we have a new group of individuals who would like to be signed up. We are going to do what we can to train these individuals and make sure that they can join our fire-fighting forces and put them to work on these fires."
The plan is to have around 400 fighters ready to relieve soldiers in the coming weeks. The government hopes to cut a few days from the usual five-day training course without sacrificing safety.
"The military's mission is to give us an opportunity to raise these resources," said Dwayne McKay of Saskatchewan Emergency Management.
Cpl. Donny Melsted, who served in Afghanistan in 2009, is happy to be of service.
"It's great to be able to help the people of Saskatchewan in their time of need," he said.
"It's tough to see the homes destroyed and the damage the fire is causing and it's great we're doing something to help put them out."
— With files from John Cotter in Edmonton. Follow @BillGraveland on Twitter
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