Vegetation is tinder-dry, and the current hosepipe bans in East Sussex, West Sussex and Cornwall, and pending drought orders in the North-west, Yorkshire and Oxfordshire are likely to exacerbate the situation.
Fire officers in Hampshire have had to call in army all- terrain fire pumps in an attempt to cope with the influx of emergencies, currently running three times higher than normal.
Six green goddesses - Bedford 4x4 pumps built in the 1950s and deployed during the nine-week fire brigade strike in 1977-78 - will be used to patrol fires on common land which have been putting an "enormous strain" on the county's regular fire rescue vehicles.
Officers took the decision to call the vehicles out of their store near Burton-on-Trent to increase the number of call-outs they could attend, and to save their modern pumps from damage.
"The ground on the commons is so dry that the modern vehicles have to race on to them day in and day out. It can cost us a great deal in extra repairs," said a spokesman.
Firefighters have also been called out to numerous garden fires ignited by sparks from bonfires.
Staffordshire Fire Service answered 709 calls in a 24- hour period earlier this week, and they say the number of grass fires is running at almost three times the average.
"Because the vegetation in this area is so dry, it burns much more readily," a senior officer said. "Then, of course, putting the actual fire out also becomes more difficult. At the moment, fires are spreading extremely quickly."
Without a long period of rain to dampen grassy areas, the fire risk will not disappear, the spokesman said.
"Thunderstorms don't actually solve the problem. Within a day or so their effect is useless and the situation is back to where we started."
In Berkshire, firemen resorted to dropping a 600-litre water-bomb from a helicopter to douse 86 acres of blazing straw near the M4 motorway.
Although weather reports for the weekend suggest that some rain is on the way, forecasters say the heatwave is set to continue.
A London Weather Centre spokesman said the respite from the scorching temperatures would be brief with high pressure building again by Monday and next week becoming increasingly hot.
"We seem to be getting these mini-breakdowns, then the weather picks up and it's very warm again," he said.
The London Weather Centre said cooler weather with some cloud and rain would arrive over northern and western parts of Britain today. England and Wales are expected to remain hot and sunny but the front would move south, bringing fresher weather and some showers tomorrow.
In Derbyshire, fire service chiefs said their crews would welcome any rainfall as this was the brigade's busiest summer since 1976.
Officers were struggling to cope with thousands of call-outs, and crews were being issued with high-energy drinks to help them combat heat exhaustion.
In the North of Scotland, firefighters have battling since the end of July to control a peat fire six miles north of Inverness. The hot weather has made the smouldering peat impossible to extinguish. "Our only real chance of putting it out totally is rain," an officer said.
"Although we really are crying out for rain to dampen down the peat, summer is not our busiest time," the spokesman added.
"Our worst scenario is a hot spring, when the trees have no sap in them and undergrowth is still dead. At the moment the sap in the trees prevents them from burning so quickly."
Meanwhile, in Britain's northern outpost, the Shetland Islands launched a publicity drive yesterday to encourage tourists fed up with the mainland heatwave to spend their holiday in "totally average temperatures" with "cooling onshore breezes".Reuse content