Standing at the top of the quad chairlift at Ski Santa Fe, I'm counting helmets with ski patrollers. It's just past noon on a semi-busy Saturday morning, and already they've hauled one skier down in a toboggan whose helmet likely made the difference between her walking away from that incident and a much worse scenario.

Purchasing and wearing a helmet is an easy and—compared to everything but your mittens—relatively inexpensive step toward increasing safety on the slopes. The National Ski Areas Association surveyed 73,000 skiers and snowboarders across the nation on helmet use, noting during in-person interviews whether the person was wearing a helmet, and found 84 percent of skiers and riders wearing helmets. The association also cites research showing that increases in helmet use correspond to reducing potentially serious head injuries from 4.2 percent to 3 percent of all injuries.

Their numbers sound high, but standing at the chairlift and tallying how many riders are wearing helmets, the scattershot headcount often seems to bear it out: The ski hats and bare heads are rare.

This year, Ski Santa Fe and Sandia Peak became the first ski areas in New Mexico to require all staff who work on snow to wear helmets. The policy applies whether they're teaching skiing, patrolling the mountain, or riding snowmobiles while making snow. Noting that ski areas in Colorado and Utah have already made this move, Ben Abruzzo, mountain manager for Ski Santa Fe, says, "We saw that we were behind the times."

Some resorts in Colorado have also begun requiring helmets for any person participating in a lesson. Ski Santa Fe hasn't yet made that move, except for all-day children's lessons at Chipmunk Corner. Helmets can be rented for an additional fee. Abruzzo points out that in the 15 years helmets have been offered, the price has only climbed from $10 to $12.

"That's the least price increase of anything, from a hamburger to a ski ticket, on the mountain," he says.

Ski manufacturers have also worked to keep helmets affordable, and prices now come as low as $60. But there's definitely a bump in price for the latest in helmet technology, MIPS. That system builds a low-friction layer into a helmet so it slides relative to the head, better protecting the brain from glancing blows or impacts that come in from an angle.

"What's pretty cool about helmet safety, in general, is that it's something that's grown more organically," says Adrienne Saia Isaac, communications and marketing director for the National Ski Areas Association.

In the 2002-03 season, just 25 percent of skiers and riders wore helmets. By 2012, that rate had nearly tripled. Rather than government regulation, adoption has been driven by ski area promotions, medical groups, professional athletes, and nonprofits like the High Fives Foundation, an organization that helps athletes who sustain life-threatening injuries in the mountains with the costs of rehabilitation and has released a series of prevention-focused videos. Moves like putting all staff in helmets are also hoped to model good behavior. And for a generation of kids who grow up in helmets, the thought is that a helmet will just be a given.

"You're instilling that this is part of what you wear to go skiing," Saia Isaac says. "It's like having boots or bindings or even skis or a board—it's natural part of your equipment."

A peer-reviewed study of 17 years of accidents found that the incidence of potentially significant head injuries declined from 1 in 4,200 to 1 in 11,000 days of activity at the same time helmet use increased.

But they do have their limits. Staff at the University of Colorado sports medicine center estimate the risk of traumatic death is 0.7 per million skier visits—and lower for snowboarders at just 0.5 percent. In the 2014-15 season, 27 of 42 people catastrophically injured in the US were wearing helmets, according to NSAA data. If a skier or rider is traveling at a speed comfortable for the average intermediate skier, striking a tree or another object will likely exceed the protection a helmet can offer.

"Helmets really are their most effective when they're used in conjunction with other best practices of staying safe on the hill, liking riding and skiing in control, and being aware of your surroundings," Saia Isaac says. "A helmet is a fantastic tool, but it's just one tool in your quiver of mitigating your risk."

Elizabeth Miller is a part-time ski instructor at Ski Santa Fe.