Water-bombing helicopters, tankers and extra crews are being moved into the open-cut mine near Morwell to protect the Hazelwood power station from the threat of fire.

Authorities warn a wind change on Wednesday morning could fan flames burning in the mine's coal pit, and push a grass fire towards the power station.

The strong winds have also prompted a high-level smoke alert, issued on Wednesday morning, for several towns in the Latrobe Valley including Churchill, Morwell, Newborough, Moe and Traralgon.

The advice, issued by the Health Department and the Country Fire Authority, has forecast extended periods of smoke in Morwell South and Morwell East, that will extend throughout the day and poses health risks to people with heart and lung conditions, infants and the elderly.

Last week, similar windy weather drove a grass fire within 400 metres of the power station, destroying rolls of conveyer-belt materials.

Incident controller Bob Barry said the firefighting effort, which has so far reduced the area on fire by 85 per cent, could "slip backwards" again, because of erratic wind conditions on Wednesday.

He said mineral earth breaks would be strengthened around the edges of the mine fire, and extra helicopters and strike teams would help crews brace for the worst.

"The Morwell community, again, is in for another rough day weather-wise," Mr Barry said.

"The south-westerly change means winds will be up for many hours."

Morwell and surrounding areas have been cloaked in toxic smog and fine ash for more than three weeks since a deliberately lit fire spotted into the Hazelwood coal mine.

Traralgon resident Troy Schaeche, who works on Latrobe Road in Morwell, said the smoke was "unbearable", and was aggravating his asthma.

"I wake up in the morning and [my breathing] is shocking," he said.

The smoke has forced him to take off eight days in the past fortnight. Being a casual employee meant he and his family were falling behind on rent.

"We have to buy food, pay bills... these things don't pay for themselves. I usually earn just over $1400 a week and this week I'll be lucky if its over $600."

The part of Morwell where Mr Schaeche works, and his home in Traralgon, do not fall within areas where people are eligible for any government assistance grants.

"I can't work, I'm losing out on money and I can't get assistance from anywhere unless I go on the dole," he said. "And I don't want to go on the dole."