It’s frequently compared to a sauna - and now the London Underground has got its own.

As the country sizzles in a record-breaking heatwave, a tiny steam room appeared at the end of a Tube compartment packed with hot commuters trying to keep cool. The installation by Currys may have appeared authentic but all was not quite as it seemed.

Set up in an out-of-service carriage at Walthamstow Pump House Museum, in London, the sauna was designed to show the extreme conditions travellers face during hot weather.

New research has revealed that 80% of commuters found the temperature on the Underground unbearable, while 76% said it was more uncomfortable than sitting in a hot sauna. Around two thirds (67%) worry about arriving at work visibly sweaty.

According to travellers, the hottest Tube lines are the Central line, followed by Northern and Victoria, with subterranean temperatures regularly exceeding 30C and passengers often advised to avoid travel unless necessary.

Julia Gater, senior buyer at Currys, said: "Anyone who has travelled on the Tube during a heatwave knows the feeling. The moment the doors close, it can feel like stepping into a sauna.

“When we discovered that three in four Londoners think travelling on the Tube without air conditioning is even more uncomfortable than sitting in a hot sauna, we wanted to bring that comparison to life in a way that would make people smile while highlighting just how extreme summer commuting can become.

“While we can't cool down the Central Line, we can help people create moments of relaxation and recovery at home. As well as technology, we offer a growing range of wellness, beauty and lifestyle products designed to help people unwind and recharge."

Shoppers who want a wellness experience at home can find a range of products at Currys including portable steam saunas, infrared sauna blankets and facial saunas with steam inhalers. There is also a wide selection of cooling devices.

London's top five hottest Tube lines (according to commuters)