Firefighters will be able to deliver food and medicine, drive ambulances and retrieve bodies to help the UK get through the coronavirus pandemic.
Fire service bosses say a new agreement between their various organising bodies reflects the “scale of the national crisis and the urgency of the response required”.
It comes as the number of people in the UK to have died with coronavirus reached 584 on Thursday, with almost 12,000 people infected.
Firefighters will continue to prioritise their main responsibilities, including emergencies such as fires and traffic collisions.
But bosses will meet weekly to talk about additional requests made by Local Resilience Forums and Strategic Co-ordination Groups.
Any firefighters involved in coronavirus-related tasks will be trained and given the appropriate personal protective equipment, according to the Fire Brigades Union, which announced the move.
The agreement, between the union, fire chiefs, and fire and rescue employers, will be in place for two months but it can be extended or shortened.
There are around 48,000 firefighters and emergency control staff in the UK.
Matt Wrack, FBU general secretary, said: “We face a public health crisis unparalleled in our lifetimes.
“The coronavirus outbreak is now a humanitarian emergency and firefighters rightly want help their communities.
“To get through this, we must find ways to work together with other emergency services. Firefighters are fantastic at teamwork, are experienced in driving emergency vehicles and, as a service rooted in the community, may be best placed to deliver essential items to the most vulnerable.
“Many fear the loss of life in this outbreak could be overwhelming and firefighters, who often handle terrible situations and incidents, are ready to step in to assist with body retrieval.
“Firefighters and control staff have always stepped in when the public has been in danger and this crisis is no different. The strain on all emergency services will be great, but we can and will get through it together.”
Roy Wilsher, chair of the National Fire Chiefs Council, said: “All fire services are working to protect communities during COVID-19 and they will use their wide range of capabilities and skills to ensure community reassurance and support; doing what they can to support people through this crisis.”
Cllr Nick Chard, fire and rescue service employers, said: “We can immediately step up our assistance to support our over stretched public sector colleagues, especially ambulance services, with our can do attitude and sense of community spirit.”