While ultraviolet (UV) radiation is generally lower in intensity in the winter months, experts remind us to w ear sunscreen, hats, and protective clothing to protect against potential skin damage. Peter A. Andersen, from San Diego State University (California, USA), and colleagues collected data on 3,937 skiers and snowboarders at 32 high-altitude ski resorts in western North America during a two-year period. The team measured direct, reflected, and diffuse UV at 487 points using handheld meters, and interviewed study subjects about their sun protection measures. The team found that sun-protection behaviors on ski slopes didn't consistently increase when UV levels were elevated.While most adults wore more sunscreen and reapplied it more often on the slopes when UV was higher, such as on sunny days at noon, they didn't often wear hats or protective clothing on those days. As well, they noted that cold temperatures, not UV levels, most influenced when skiers and snowboarders were more adequately protected, such as more fully covering their bodies and using goggles. Explaining that: “The strongest predictors of UV were temporal proximity to noon, deviation from winter solstice, and clear skies,” the researchers write that: “In future sun safety promotions, adults should be encouraged to wear sunscreen on cloudy days because UV is still high and conditions can change rapidly. They need reminders to rely more on season and time of day when judging UV and the need for sun safety.”