It's a long, hot slog fighting a fire as big and complex as the one in the Hawke's Bay in the blazing heat. But it's also satisfying work.

Yesterday firefighters worked shifts of up to 15 hours to battle the inferno south of Hastings, which has now burnt through 500ha of land.

"It's really, really hot work. It's incredible. Particularly in the grass fire areas, there's absolutely no shade. People are exposed to very high temperatures and the sun [beats down] all day long," National Rural Fire Authority incident controller John Sutton said.

Yet despite the harsh working conditions morale is high.


"The thing about firefighting is that you can see the results of your efforts behind you, so it can be satisfying," Sutton told the Herald.

Crews worked through the night to keep the fire at bay, using a bulldozer to clear debris.

Two new blazes had sprung up overnight but fortunately firefighters were able to extinguish them.

Firefighters from as far away as Northland and Queenstown have flown in to help local rural and urban crews.

"We've had enormous offers of support," Sutton said.

Helicopters were sent up at first light this morning and about 100 staff from the rural fire authority and fire service will be on the ground fighting the fire on four fronts today.

Three sections of the fire are well contained but one, at Waimarama, is still threatening a pine plantation and nearby homes.

Sutton said it was the complexity of the fire rather than its size that made it hard to keep under control.

"We've got an enormous amount of work [to do] to get that fire out. There are still hot areas that we haven't been able to extinguish. Until they're extinguished they still pose a risk."

The changeable weather had the potential to cause chaos, too.

"At the moment it's reasonably benign this morning, not too hot, a little bit overcast and not too much wind," Sutton said.

"[But] it's predicted to blow almost as strong as yesterday, with gusts up to 50km/h to 60km/h. If that manifests we're going to have problems."

"Firefighters just want to put the fire out but in these temperatures and conditions they've just got to look after themselves and we've got to stress that they've got to pace themselves. It's a long day."

Crews would be at the scene for at least a few more days to make sure the fire was completely out.

Police and civil defence were helping evacuate residents and the Salvation Army was providing the firefighters with meals, Sutton said.

The Hastings District Council was also supporting the effort.