Sagging powerlines are believed to have started one of several hedge fires in Hawke's Bay in recent days.
On edge firefighters are warning people in the region to be careful as the mercury rises above 30C, and are refusing all fire permits in the region over the next few days.
Firefighters were called to the large hedge fire beside powerlines in Te Awanga on Sunday afternoon, believed to have been caused by a sag in the lines in the heat.
Farmer Mark Warren was at a nearby winery when he noticed the smoke and quickly sprung into action.
He hopped in his car and towed several of the vehicles out of the way of the flames and called the fire service and another bystander got in touch with the powerlines company.
"It's amazing how good country folks come together during dramas."
Last week's large hedge fire near Fernhill, Hastings, in which six homes were evacuated, was also still under investigation, principal rural fire officer Trevor Mitchell said.
"We are considering that it could be suspicious. We haven't managed to identify a cause which is obviously of concern."
Firefighters had also been called to several unpermitted fires which had gotten out of control, he said.
He asked that people take extra care - the region is currently in a restricted season, meaning that fires cannot be lit without first obtaining a fire permit.
"The La Nina weather patterns may give us a few tropical lows which we are hoping will give us a bit of moisture."
But with little to no rain expected in the coming days, Mitchell said they had suspended current active permits for the next few days.
"The normally dry areas are getting very dry - Central Hawke's Bay, coastal areas and the Heretaunga Plains.
"We are at the time of year where people need to be extra careful."
On Friday, firefighters were called to an old burn in Central Hawke's Bay that had been buried a year ago and been burning underground ever since.
Mitchell said anyone who had a large burn pile over the winter should double check that it is completely out.
"We ask people to advise their local power authority if powerlines are close to trees or other vegetation and avoid spark hazardous activities such as mowing and topping during the heat of the day.
"If it is windy, don't light any fires in the open at all and ensure braziers, pizza ovens and charcoal fires are supervised and completely extinguished."
He said the region was having a great summer and they wanted people to enjoy it safely.
People should call 111 immediately if there was any sign of fire, he said.