In one recent case, a 12-year-old boy developed a sponge-patterned skin discolouration on his left thigh after playing computer games for a few hours every day for several months.

‘He recognised that the laptop got hot on the left side; however, regardless of that, he did not change its position,’ Swiss researchers wrote in the respected medical journal Pediatrics.

Another case involved an American law student with a mottled discolouration on her leg.

Her doctors was stumped until they learned the student spent about six hours a day working with her computer propped on her lap.