It comes as the number of people killed in fires across England rose by 8% over the last year.
The Fire Brigades Union warned fire and rescue services "are operating in a state of emergency" and urged the Government to invest in more firefighters.
New figures released by the Ministry of Housing, Communities and Local Government show there were four fire-related fatalities recorded by the Devon and Somerset Fire and Rescue Service in the year to March.
This was in line with a year earlier, but less than a decade earlier, when there were 10.
Nationally, there were 271 fire-related fatalities in the year to March, and 251 a year earlier. This was also a 3% an increase compared with the 264 a decade ago.
Of the fatalities in Devon and Somerset, three were in dwelling fires. The other was classed as either 'other buildings' or 'other outdoors'.
Steve Wright, general secretary of the Fire Brigades Union, said: "Cuts to emergency services cost lives.
"Firefighters work tirelessly to keep the public safe, but the loss of one in five firefighter posts to cuts since 2010 means that services are severely overstretched and under-resourced.
"Combined with a crisis in building safety caused by decades of deregulation, as exposed by the Grenfell Tower fire, this is a recipe for disaster. The tragic and avoidable consequence is that fire related deaths are increasing.
"Cuts imposed by Labour this year could see the loss of a further 2,300 firefighter posts.
"The Government must stop this continued austerity and provide the investment urgently needed to save lives."
The figures also show there were 3,514 fires reported in Devon and Somerset in the year to March, a slight decrease on the 3,517 a year earlier.
Across England, the number of fires attended by fire and rescue services increased by 3%, to 142,494. However, this was a decrease of 8% compared with 10 years ago.
There were also 2,958 people rescued from fires, an increase of 4% on the previous year.
A spokesperson for the National Fire Chiefs Council said fire and rescue must not become "the forgotten emergency service", with firefighters increasing having to deal with extreme weather and "risks from new energy technology".
They added: "Fire and rescue services are under increasing pressure, responding to a growing number of 999 incidents despite a shrinking workforce.
"If you want evidence of how stretched some services are, you only need to look to this summer’s wildfires which saw a number of services declaring major incidents and having to call on support from other services across the country to deal with the demand placed on their already stretched resources."
"The world has changed; the ask of fire and rescue services is changing. We’re asking the Government to ensure there’s the funding there to underpin this crucial service."
An MHCLG spokesperson said: "Any fire-related death is a tragedy, and we are working hard to support our fire services.
"That’s why standalone fire and rescue authorities will receive an increase of almost £70 million next year to keep communities safe.
"We continue to work closely with the sector to ensure fire and rescue services have the resources they need, so we can support our brave firefighters and deliver better public services through our Plan for Change."