Balancing your laptop on your knees could cause permanent discolouration of the skin and, in rare cases, cancer, doctors have warned. The heat generated by the computers can cause a nettle sting-like rash — a condition named 'toasted skin syndrome'.

Have you ever worked on your laptop computer with it sitting on your lap, heating up your legs? If so, you might want to rethink that habit. Doing it a lot can lead to "toasted skin syndrome," an unusual-looking mottled skin condition caused by long-term heat exposure, according to medical reports.

Erythema Ab Igne: "Toasted Skin" syndrome This condition occurs most commonly in women past middle age.