MADRID/LISBON: Britain was heading for its highest temperatures on record and firefighters battled blazes across southern Europe as a heatwave sent people hunting for shade and compounded fears about climate change.

In Spain, a wildfire raced across a field and engulfed a excavator near the northern town of Tabara, forcing the driver to run for his life as flames burned the clothes off his back. 

In Portugal, half the municipality of Murca was on fire and the bodies of an elderly couple trying to flee had been found inside a "completely charred vehicle," the mayor told local broadcaster SIC. 

In southern Europe there were some signs conditions were starting to ease after days of blistering highs that have caused hundreds of deaths and left the countryside dangerously dry, authorities said.

But the heatwave was moving north.

Belgium and Germany are expecting the heatwave to hit them in coming days, while temperatures nudged 38C (100 Fahrenheit) in southern England on Monday and are forecast to hit a record-breaking 40C (104 F) on Tuesday, according to Britain's Meteorological Office. 

British train companies cancelled services and some schools closed while officials urged the public to stay home and the government triggered a "national emergency" alert.

Flights were suspended at Luton airport after staff identified a "runway defect". The hot weather had melted the runway at the Royal Air Force's Brize Norton air base, Sky News reported. 

Sales of electric fans, hoses, air conditioning units and sprinklers are soaring, retailers said.

"We hoped we wouldn't get to this situation but for the first time ever we are forecasting greater than 40C in the UK," said climate attribution scientist at the Met Office, Dr Nikos Christidis.

"Climate change has already influenced the likelihood of temperature extremes in the UK. The chances of seeing 40C days in the UK could be as much as 10 times more likely in the current climate than under a natural climate unaffected by human influence," he said.

'WE HAVE NOTHING'

Wildfires raged across Portugal, Spain and France and authorities warned there was a risk of more as tinder-dry conditions persisted.

Spain was facing the last day of a more than week-long heatwave, which has caused more than 510 heat-related deaths, according to estimates from the Carlos III Health Institute.

In Tabara, locals said the driver of the excavator - a man they identified as Angel Martin Arjona - had been trying to dig a trench between the fire and buildings.

But orange flames surrounded the vehicle. TV footage showed him emerging from the blaze, tripping, then scrambling to his feet as people shouted out to him and a firefighter ran up to help.

The driver was airlifted to hospital with burns, witnesses said, though there were no detailed reports on his condition.

In El Pont de Vilomara in Catalonia, evacuees gathered outside a civic centre, among them retiree Onofre Munoz, 69, who said that his home and van had been completely destroyed.

"We bought the van when I retired and now it's totally scorched. We have nothing," he said.

EU SENDS SUPPORT

In Portugal, temperatures dropped over the weekend, but the risk of wildfires remained very high, the Portuguese Institute of Meteorology said.

Around 1,000 firefighters, backed by 284 vehicles and 18 aircraft, were battling 10 wildfires, mainly in northern regions, authorities said.

The EU sent a firefighting plane to Slovenia over the weekend, adding to recent deployments to France and Portugal.

"We continue of course to monitor the situation during this unprecedented heatwave and will continue to mobilise support as needed," spokesperson Balazs Ujvari told a briefing.

The bloc is in talks with manufacturers to buy more firefighting planes, the EU head of crisis management told Reuters. 

In the Gironde region in southwestern France, fires had destroyed 14,800 hectares (37,000 acres), local authorities said on Monday. More than 14,000 people have been evacuated from the area. France has issued red alerts, the highest possible, for several regions, with residents urged "to be extremely vigilant".

In Italy, where smaller fires have blazed, forecasters expect temperatures above 40C in several regions in coming days.

Switzerland also suffered the effects of the heatwave. Axpo, the operator of the Beznau nuclear plant, said on Monday it was forced to reduce output so that it does not overheat the Aare river from which it draws its cooling water.