Using a tanning bed to get that perfect glow is far riskier than we may think, according to findings by Northwestern Medicine and the University of California, San Francisco published Dec. 12 in the journal Science Advances.

Tanning beds are cosmetic devices that have ultraviolet (UV) lamps that produce an intense darkening of the skin when people lay in them.

The new research looked at thousands of medical records to compare melanoma rates in people who used tanning beds and those who did not, and found nearly a threefold increase in the risk of melanoma among tanning bed users. Melanoma, while treatable if caught early, is the most lethal form of skin cancer and is responsible for about 11,000 deaths in the U.S. each year. It is more common among women.