As part of the military deployment, Gurkha logistics teams equipped with water tankers and military engineers are now assisting fire services in South Wales.
Andy Burnham has promised more military personnel will be deployed elsewhere if needed.
Crews in England and Wales tackled multiple blazes on Friday and an emergency alert was sent to millions of phones.
A total of 1,017 wildfires have been recorded in England and Wales this year, according to data shared by the National Fire Chiefs Council (NFCC), which matches last year’s record.
As well as devastating blazes in the West Midlands which saw dozens of homes destroyed, fire crews have been in action across the two countries.
In Wales, a major incident was declared near Llandovery, Carmarthenshire, after dozens of homes were evacuated and roads closed.
In Hampshire, firefighters have spent a sixth day tackling a wildfire in the New Forest, which broke out on Sunday.
Sixteen emergencies were tackled by Norfolk Fire and Rescue Service on Thursday afternoon, including a fire at Mousehold Heath in the city.
On Friday evening, an emergency alert was sent to mobile phones warning of a “very high risk of wildfires nationally” across England and Wales.
The message asked residents, landowners and visitors to not undertake any activity that could cause a fire “including disposable barbecues, firepits, garden incinerators of fireworks”.
It was the most extensive use of the system to date, according to the government.
All retailers will be receiving guidance about the change, which will be kept under review, Burnham told the BBC.
He also said some of the wildfires burning across the country will have been started by disposable barbecues.
Speaking to BBC Radio 5 Live’s Matt Chorley, the prime minister said: “We’ve got 37 fires across England and Wales right now, four of them are major incidents.”
He added: “We’re going into a difficult weekend, please just think about the situation that we’re in.
“Britain is a tinderbox right now. Setting a fire in any outdoor setting of any kind is a risk to other people’s homes, it’s a risk to other people’s lives, don’t do it, please don’t do it.”
Many large retailers and supermarkets had already voluntarily stopped selling the devices under a framework agreed in 2023, external between fire chiefs and the British Retail Consortium.
It said that retailers should suspend sales once an extreme heat event has been declared as imminent, or in response to “reasonable, evidence based” requests from local councils.
“We have a fire and rescue service across the country that isn’t properly set up to deal with these incidents,” Burnham said.
“We don’t have the capability in the way that we should have to fight these fires.
“There’s thousands of firefighters out there today doing back-breaking work, in full kit, in the most difficult conditions”, he added.
He said the UK must face up to the “changing climate” and transition to “more clean energy”.
His comments came ahead of the appointment of Baroness Blake of Leeds as fire minister.
Friends of the Earth urged the prime minister to tackle the “root cause” of the “climate emergency” that is fuelling this summer’s extreme weather events.
“Without urgent action to curb the carbon emissions driving this crisis, future heatwaves, droughts and wildfires will only get worse and the ability for future generations to adapt will disappear” the environmental group warned.
Burnham was speaking during a visit to Stourbridge to see the impact of a devastating blaze.
As the UK experienced its hottest day of the year on Thursday, residents fled their homes when fires spread through dry grass and tore through houses.
West Midlands Ambulance Service said it treated 54 casualties at eight different fires across the region. Nineteen people were taken to hospital for treatment.
In 2025, fire and rescue services in England and Wales broke a new record when they responded to nearly 1,000 wildfire incidents, with the NFCC warning at the time that climate change is increasing their risk and severity.
The conditions the UK is experiencing so far this summer also mirror the warnings given by climate scientists that human-induced climate change would lead to more frequent and intense heatwaves, as well as potential summer droughts.
In England, the Rugby Football Union has delayed the start of the community rugby season because of concerns about player welfare and pitch conditions because of the drought conditions.
