Multiple heat warnings remain in place across the North East as Wangaratta is expected to swelter through a fourth consecutive day of more than 40-degree temperatures.

The region has been subject to the worst heatwave in Victoria since 2009 according to VicEmergency and it was expected 40-plus degree temperatures would hang around within Wangaratta until at least Sunday.

A Total Fire Ban was issued for the region on Wednesday and a Bureau of Meteorology heat warning remains in place with the severe heatwave expected to peak.

According to the Bureau, parts of the Alpine Shire and Towong Shires were forecast for extreme heat, before gradually easing by Sunday.

“Severe heatwaves can be dangerous for many people, especially older people, babies, children, pregnant and breastfeeding women, people with medical conditions and people who are unwell,” the Bureau's advice message read.

Total Fire Bans were in place statewide on Sunday, Monday and Tuesday as record-breaking temperatures hit the northern parts of Victoria.

“Now is the time to have your bushfire plan ready, talk with your family about what you’ll do if a fire starts, and be prepared to act early,” CFA chief fire officer Jason Heffernan said.

"Conditions will make it difficult to suppress new fire starts, as well as providing a challenge for firefighters already working hard on containing existing fires.

“Make sure you’re staying hydrated and checking in on vulnerable family, friends and neighbours.”

A high fire danger rating was forecast for the North East for the rest of the week, with Wangaratta expected to reach 40 degrees each day prior to Sunday.

So far in January, Wangaratta is averaging a mean maximum temperature of 34.3 degrees.

Rural City of Wangaratta Council have offered free swimming at the Wangaratta Sports and Aquatic Centre and encourage the community to stay cool and hydrated.

In the south west of the state, a major fire in the Great Otway National Park continues to burn out of control, with multiple evacuation warnings current in the area.

People with asthma are advised to take their prescribed preventer medication and keep their reliver close at hand, with air pollution from bushfires across the state increasing the risk of asthma attacks.

Asthma Australia chief executive officer Kate Miranda said bushfire smoke can have serious health impacts for anyone with asthma, even at low levels.

“People with asthma should minimise smoke exposure, follow their Asthma Action Plan, take their reliever or anti-inflammatory inhaler as prescribed, and watch their symptoms closely,” she said.

WorkSafe chief health and safety officer Sam Jenkin said employers must prepare for the conditions and make any accommodations needed to ensure tasks are carried out safely or where necessary, postponed.

"Working in severe or extreme heat can easily lead to dehydration and heat illnesses such as heat rash, fainting, heat exhaustion and heat stroke – which is a life-threatening condition," he said.

"It is imperative employers plan ahead and take all reasonable steps to protect their workers, particularly those exposed to the elements or working in spaces without ventilation or air conditioning."

Stay up to date with the latest weather warnings via: https://www.bom.gov.au/weather-and-climate/warnings-and-alerts