Firefighters are battling double the usual number of blazes as the continuing hot weather creates tinder-dry conditions.

And the heatwave is taking its toll on their health, a union has warned, as it emerged that two firemen collapsed in “extraordinary temperatures” at a blaze in Bradford this week.

Yesterday was another busy day for the district’s fire crews as they battled a serious house fire in Undercliffe, Bradford, among a host of call-outs.

It follows a blaze which destroyed the Pakeeza supermarket in Ingleby Road, Bradford, on Thursday with 70 firefighters called out to quell the flames.

Two of these firefighters collapsed at the scene from heat exhaustion and dehydration, Dave Williams, of the Fire Brigades Union, revealed.

West Yorkshire’s fire crews have been called out to 618 fires so far this month, exactly double the number they battled in the same period last year.

The greatest increase has been in minor blazes, such as bin or rubbish fires, which have nearly trebled.

And this year alone, they have been called out to 54 moorland fires.

Mr Williams said staff members’ health in the heatwave should be of paramount importance, especially in light of the recent tragedy in the Brecon Beacons, in which two TA soldiers died while training in hot conditions.

He said: “It’s starting to take its toll. It’s a physically demanding job and the heat doesn’t help.

“You don’t tend to realise until it’s too late that you’ve probably been pushing yourself too hard.

“Firefighters are firefighters and they will get on with it and not mention it until it’s too late. They just muck in and get it done.

“That leaves it down to us. We need safeguards to make sure people are looked after.”

A spokesman for the fire service said the firefighters who had been taken ill were seen by paramedics at the scene.

She said: “They were suffering from the effects of working in the intensive heat of a large fire during the extraordinary temperatures we are experiencing at present.”

Area manager Mick Smith added: “The safety of firefighters is always at the very top of the agenda for West Yorkshire Fire and Rescue Service in all weather conditions.

“This is a difficult period, working through extraordinary temperatures in hot fires, but firefighters’ health and welfare is an absolute priority at every incident.”

The public are advised to take rubbish home after picnics, especially glass bottles which can magnify the sun’s rays, and never throw cigarette ends on the ground or start a fire in the countryside.

On Thursday, five back-up engines had to be manned by off-duty firefighters across the county.

The Met Office has raised heatwave alerts in more parts of Britain as the sunshine and soaring temperatures show no sign of abating. Yorkshire remains on a level two alert, which is triggered when temperatures are in danger of hitting 29C for two days running.

Bradford Council was even sending out its gritters to spread sand to prevent road surfaces from melting.

Meanwhile, Yorkshire Ambulance Service has urged people to take extra care around open water.

Paul Mudd, acting director of operations, said rivers and reservoirs could have treacherous undercurrents, while the temperature of deep water could be dangerously low even during a heatwave. He said: “Several lives have already been lost this year across the UK and we don’t want to see anyone else hurt or injured so the message is simple; enjoy the summer, stay out of open water and stay safe.”