It is the final day of the Six Nations championship at Twickenham stadium. As a fan enters the turnstile she hears a beep. The security system has detected an above average body temperature and, despite paying £250 for a ticket, she is turned away.

It might sound like a far-fetched scenario, but fever surveillance could be a reality facing Britain once Covid-19 has stabilised.

“It is going to be the ‘new normal’,” says Frank Pennisi, Industrial Business President at Flir.

The $4.6bn (£3.6bn) thermal camera giant has seen “exponential” demand since the World Health Organisation declared Covid-19 a pandemic in March.

Their temperature guns were held aloft by Emirates Airlines stewards to check passengers travelling from London to the US in recent weeks. The WHO uses the technology to spot check staff working from its headquarters.

Transit hubs like airports, train stations, border checkpoints along with hospitals and assisted care facilities have been using the systems for some time. And now, Amazon, Carnival Cruise lines and Rolls Royce among others are counting on thermal imaging technology to keep operations running.

“I would liken the Covid-19 pandemic to terrorism, which was always seen as an existential threat,” Pennisi says. “It wasn’t until 9/11 that there was a newfound desire to put preventative measures in place, and I believe that is what will happen now with Covid-19. It is no longer a threat. It is real, and people want to prevent it.”

Indeed, the small yet mighty thermal imaging industry has certainly been swamped in recent weeks.

Cambridge-headquartered Thermoteknix Systems is racing to supply parts for thermal cameras, with sales in the first quarter of this year three times higher than a normal year, according to Richard Salisbury, the medical doctor who founded the company 30 years ago.