It's springtime and a young person's fancy turns to... indoor tanning beds. And yes, that's completely insane. Researchers estimate that indoor tanning may cause upwards of 400,000 cases of skin cancer in the US annually, yet approximately 7.8 million adult women and 1.9 million adult men in this country use tanning beds. In 2015, all that indoor tanning-induced skin cancer lead to a total economic loss of $127 billion over the lifetime of those patients. Unlike other well-documented bad behaviors, such as cigarette smoking or cleaning your gun while drinking tequila, indoor tanning is actually on the rise.