"Hot legs" isn't just another term for good-looking gams. It can be a warning sign of a medical condition that affects users of laptop computers.
The condition, dubbed erythema ab igne or "Toasted Skin Syndrome," arises when people rest a hot laptop on their laps for an extended period of time.
Sounds ridiculous, but recent cases suggest it's no joke.
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.
In another case, a Virginia law student sought treatment for the mottled discoloration on her leg.
Dr. Kimberly Salkey, who treated the young woman, was stumped until she learned that the student spent about six hours a day working with her computer propped on her lap. The temperature underneath registered 125 degrees.
That case, from 2007, was one of 10 laptop-related cases of dermatosis reported in medical journals in the past six years.
The condition is generally harmless but can cause permanent skin darkening. In very rare cases, it can cause damage leading to skin cancers.
The danger was highlighted by Swiss researchers Andreas Arnold and Peter Itin in an article today in the journal Pediatrics.
Got a laptop? Don't use it on your lap. Or do as the researchers from University Hospital Basel suggest and put a carrying case or heat shield under it.
This article originally appeared on CBSNews.com.