We know: Sunscreen can be a hassle. It has to be applied before you leave the house (a forethought that isn’t second nature to many of us). You have to lug it around and keep reapplying. But the extra effort is worth it: It can add years to your life. Even those who tan easily can’t afford to skip it. With that in mind, here’s what you need to know about sun protection in Colorado, thanks to doctor Theresa R. Pacheco, the medical director of the CU Cosmetics, which is part of the University of Colorado School of Medicine’s Department of Dermatology.

Be Choosey: When picking a sunscreen, two factors are of particular importance. According to Pacheco, broad-spectrum protection is key, along with a Sun Protection Factor (SPF) of 30 or higher. Broad-spectrum protection minimizes Ultra Violet A, or long-wave (UVA) rays, which contribute to skin aging. SPF 30 protects against Ultra Violet B, or shortwave (UVB) rays, which cause sunburns. Protecting against both types of rays combats potential skin cancer. (Note: Doubling your SPF doesn’t double your skin protection, but does measurably increase it.)

Think Ahead: Sunscreen should be applied 10 minutes before hitting the rays, and then reapplied every two hours.

Waterproof Yourself: Even waterproof sunscreen can’t last longer than 80 minutes in the pool, which means you’ll need to apply more frequently if you’re wearing your floaties. Pacheco also recommends using waterproof sunscreen during outdoor workouts because of increased sweat.

Locals Warning: Our state’s altitude and climate mean you should take extra precautions. Along with dryness, which can leave skin more exposed to sun damage, the altitude makes the need for sunscreen critical, even on cloudy days. “The higher the elevation, the higher the level of solar UV radiation,” Pacheco says. “For every 1,000 feet in elevation, one experiences five percent more solar UV radiation. So, in Denver, which is at 5,280 feet in elevation, we are exposed to 26.4 percent more UV rays.”

Our best advice: treat sunscreen like a prescription. Apply liberally, often, and with care.

—Image courtesy of Shutterstock