'Toasted skin syndrome' is a condition, researchers warn, would affect the skin if a laptop rests too long on the lap.
A medical report has found that placing the devices next to skin for long periods of time can lead to "toasted skin syndrome," an unusual-looking mottled skin condition caused by long-term heat exposure.
In one case, a 12-year-old boy developed a sponge-patterned skin discoloration on his left thigh after playing computer games a few hours every day for several months.
Another case involved a Virginia law student who sought treatment for the mottled discoloration on her leg.
Dr Kimberley Salkey, who treated the young woman, couldn't work out the source of the problem until she learned the student spent about six hours a day working with her computer propped on her lap.
The temperature underneath registered 125F (52C).
The case, from 2007, is one of 10 laptop-related cases reported in medical journals in the past six years.
The condition also can be caused by overuse of heating pads and other heat sources that usually aren't hot enough to cause burns.
While it is usually harmless, it can cause permanent skin darkening.
In very rare cases, it can cause damage leading to skin cancers, said the Swiss researchers, Drs. Andreas Arnold and Peter Itin from University Hospital Basel.
They do not cite any skin cancer cases linked to laptop use, but suggest, to be safe, placing a carrying case or other heat shield under the laptop if you have to hold it in your lap.
The study has been published in the journal Pediatrics.