Caught in a mountain snowstorm? Here’s what to do when the weather turns.

The 911 text was brief: “Please help me.” 

A 37-year-old woman hiking alone on Colorado’s Four Pass Loop sent the message late Oct. 29, as she struggled to navigate snowy conditions near Frigid Air Pass, a 12,400-foot crossing between Aspen and Crested Butte. Her phone battery was down to 10%. 

CareFlight of the Rockies accepted the call to help locate the hiker, and Crested Butte Search and Rescue also dispatched a ground team of five rescuers on foot. Around 3 a.m., they reached the top of the pass and spotted the hiker below. They also found deep snow, steep terrain and avalanche concerns that complicated the descent. By 6 a.m., rescuers had reached the hiker, who was suffering from exposure and could no longer walk on her own.

The rescue ultimately required a helicopter hoist operation involving the Colorado Army National Guard and specialized rescue technicians from Vail Mountain Rescue Group. The woman was safely extracted later that morning.

The incident is a reminder of how quickly conditions can become dangerous in Colorado’s high country, particularly during the shoulder season, when snow, wind and plunging temperatures can turn a familiar route into a difficult or impassable one.

Even experienced, well-equipped backcountry travelers can find themselves in trouble when mountain weather changes unexpectedly. And while checking forecasts, carrying the right gear and leaving a trip plan with someone at home are essential precautions, they don’t answer a more immediate question: What should you do when you’re already out there and a storm rolls in, or the conditions are not what you expected?

Here’s what Colorado mountain safety organizations recommend.

Abandon the summit. Don’t wait for weather to get worse.

The first decision is often the most important: Recognize when conditions are deteriorating and change your plans.

If clouds are building, temperatures are dropping, winds are picking up or precipitation is starting, don’t push toward a summit or try to squeeze in one more section of a route. If conditions are still safe for travel, consider turning around before visibility and footing deteriorate.

Winter weather in particular can change the difficulty of a familiar route quickly. The National Park Service advises hikers to turn around when a trail becomes too difficult to travel safely or when they lack the appropriate gear.

In Colorado, afternoon thunderstorms are common during summer, but winter weather can move in at any time of day. Above treeline, there’s little protection from wind, lightning or falling snow.

Understand how new snow changes the terrain.

A significant snowfall doesn’t just make hiking more difficult but can create new avalanche hazards, sometimes within hours.

Theresa Blake Graven, public information officer for the Colorado Avalanche Information Center, said heavy snowfall and strong winds can rapidly create unstable snow on steep slopes. Early in the season, even a relatively small avalanche can be dangerous because it can carry someone into exposed rocks or other obstacles.

After significant snowfall, Graven recommends avoiding steep, snow-covered slopes, particularly where wind has loaded snow, as well as areas below steep slopes where avalanches could run. Terrain with shallower slopes — less than about 35 degrees — that isn’t connected to avalanche paths is generally safer.

Constant monitoring of changing conditions is key to good decision-making, Graven said.  

“The key takeaway is that conditions can change during an outing,” she said. “A route that was relatively stable on the ascent may be dangerous on the way down, so backcountry travelers should continually reassess conditions and be prepared to change their plans.”

If visibility disappears, stop moving.

It’s tempting to keep going when the weather turns, particularly if you think you’re close to the trailhead or a familiar landmark. But in a whiteout, even experienced hikers can become disoriented and lose their route.

If you can’t see where you’re going, stop. Find the safest nearby shelter you can, and avoid wandering in search of a better route unless your current location presents an immediate danger.

The National Park Service recommends that hikers caught in a snowstorm stop their activity, find nearby shelter and stay put rather than risk becoming lost.

The Colorado Search and Rescue Association offers similar advice for people who are lost: Slow down, make a plan and avoid continuing toward a goal. If you’ve already contacted emergency services, stay where you are. Rescuers will use your last known coordinates, and moving can make it harder for them to find you.

Get out of the wind and stay warm.

Cold temperatures, wet clothing and wind can quickly lead to hypothermia, even when temperatures aren’t far below freezing.

Put on additional layers before you get cold. Change out of wet clothing if you have dry options. Use your sleeping bag or other insulating gear to retain body heat, and put something — like a backpack or sleeping pad — between yourself and the cold ground.

The National Park Service recommends wearing layers made of wool or synthetic materials rather than cotton, which absorbs moisture and loses its insulating ability when wet. It also recommends carrying an extra set of dry clothing in a sealed bag.

If you have a tent, tarp or emergency shelter, use it to get out of the wind and precipitation when it’s safe to do so. A tent can provide protection from wind and snow, but it is not a substitute for choosing safe terrain. Avoid camping in gullies, drainage channels or other locations where water or snow could accumulate.

Watch for signs of hypothermia in yourself and others, including uncontrollable shivering, confusion, difficulty speaking and stiff muscles. The National Park Service warns that prolonged exposure to cold can lead to serious illness, even when someone has appropriate clothing.

Even if help is on the way, challenging conditions can delay rescue. In their incident report from Frigid Air Pass, Crested Butte Search and Rescue reminds people to “do their best to be prepared.”

“As this rescue demonstrates, help can take considerable time to arrive, especially in remote locations and challenging conditions. Even with helicopters and other specialized resources available, an evacuation is never guaranteed to be quick or straightforward.

“So throw that extra puffy in your pack!”

Call for help sooner rather than later.

If you’re lost, injured, unable to safely continue or concerned that someone in your party is becoming hypothermic, contact search and rescue. Don’t wait until the situation becomes life-threatening.

Call or text 911 if you have cell service. The Colorado Search and Rescue Association recommends texting when possible because it uses less phone power. In addition to a cellphone, carry a satellite messenger which has better battery life and can be used to send an SOS.

Be prepared to share your GPS coordinates, your last known location, the number of people in your group and the nature of the emergency.

Once you’ve contacted rescuers, follow their instructions. They may be able to advise you on whether to stay put, move to a safer location or take other steps while waiting for help.

Keep your phone warm inside your jacket if the battery is draining quickly in the cold. The Colorado Search and Rescue Association also advises limiting unnecessary calls and messages to preserve battery life and maintain an important communication link with rescuers.

Make yourself easy to find.

If you’re waiting for rescue, stay together if you’re traveling in a group. Keep your emergency shelter visible and use a whistle, headlamp or other signaling device to attract attention.

If you have a brightly colored jacket or other high-visibility item, keep it accessible. Use your phone or satellite device to share your location with rescuers, and avoid moving unless they direct you to do so or your current location is unsafe.

The Colorado Search and Rescue Association emphasizes that staying put after reporting an emergency is one of the most important things someone can do. Moving away from the last known coordinates can delay a rescue.