Firefighters who tackled the Glasgow School of Art have told of battling a “volcano” blaze which left some on their hands and knees, taking days to recover from the sapping heat.

Ewen Macsween, whose bravery during inferno was hailed around the world, said the heat was overwhelming.

Mr Macsween, 42, was seen getting as close to the fire as possible in dramatic scenes as the GSA’s Mackintosh building burned.

He was paired up with with Barry Wood, 43, in a team that pumped thousands of gallons of water into the burning landmark from a 60ft platform.

READ MORE: Revealed: the missing safety checks at ravaged Glasgow School of Art fire

Their crew from Springburn fire station first thought they were racing to a false alarm when they got the call a week ago on Friday around 11.30.

Mr Macsween said it was the toughest in his 13-year career.

The firefighters told how the flames surged so high that they were forced to retreat on their aerial rescue platform.

It took them days to recover from a gruelling ten-hour shift at the ferocious blaze, the Sunday Mail reported.

Mr Macsween, from Skye, said: “We all thought there was a mistake when we were told it was the School of Art.

“But when we made our way there, the skyline was lit up. It was incredible.

“It’s the hottest temperatures I’ve ever experienced.

"It felt like we were battling a volcano."

READ MORE: Revealed: the missing safety checks at ravaged Glasgow School of Art fire

He said: "We could only spend a maximum of 30 minutes in the cage. The heat was so intense.

“There was a lot of explosions and the fire was burning. What you’re hearing is like a roar.”

About 120 firefighters fought the flames in the second blaze to hit the Mackintosh building since 2014, destroying £35million of repairs and gutting the rest of the building.

Mr Wood said: “We knew it was the School of Art but we thought, ‘This can’t be right’.

“It’s unique being in a cage above a fire. Sometimes there were surges and we had to back away

“The intensity was quite something.

“There were things crashing and falling. We were at maximum height and maximum outreach.

“We were as close as we could be because the appliances would have melted.

“It was an incredible effort. There were 120 men and by the end some were virtually on their hands and knees.

“They were black, filthy and soaking.”

READ MORE: Revealed: the missing safety checks at ravaged Glasgow School of Art fire

Mr Macsween, the first to climb into one of six aerial platforms deployed to help, said: “We knew in a building that size, if the blaze is through the roof, you need to get above it and get a high volume of water on it to contain it.

“That sort of temperature saps you.

“The heat meant you had to turn your face away and put your visor down.

“I’ve never felt anything like it.

“For a long time you feel hot but all of a sudden it changes and you feel as if you’re on fire.

“That’s the time you get back and get some cool air around you.

“But you can’t stop or it will flare up again.

“At the height of the fire, you didn’t know how much water was evaporating before it even got to the fire.

“It takes you a few days to get over it.”

The pair finished their shift with a traditional cup of tea.

Mr Wood added: “Everyone is sad about the building but from our point of view, no one died so you can take a bit of comfort.”