A hiker along one of Colorado's most beloved back country treks, near Conundrum Hot Springs, prompted a search-and-rescue response team to try to get her out over the weekend.

The cause? Altitude sickness.

About six miles along the Conundrum Creek Trail in Pitkin County, a young woman was suffering from 'severe' altitude sickness and unable to get herself out, a caller told the Pitkin County Sheriff's Office about 5:00 in the evening on Oct. 22.

Mountain Rescue Aspen was mobilized, and a medical helicopter was set on standby.

Shortly after, the rescue team made contact with the young woman on foot, who was slowly making her way out.

MRA accompanied her to the trailhead, where she refused medical treatment and left the area for a lower elevation.

Altitude sickness can cause headache, upset stomach, feelings of fatigue, dizziness, and sleep disruption, according to the Mayo Clinic. It can also be deadly.

Earlier this year, in August, a 20-year-old woman died from altitude sickness while hiking in the same area.

READ: 20-year-old woman dies while hiking to Conundrum Hot Springs

Take precautions if you plan to travel, or exercise, at altitudes from 4,921 to 11,483 feet and above.

Stay well hydrated, as dehydration decreases the body's ability to acclimatize to high altitude.

If you are planning a vacation (e.g. skiing or trekking), allow for an extra day or two during the trip so that members of your group can adjust to the effect of new altitudes, the Mayo Clinic recommends.

Get lots of rest ahead of high-altitude travel and have a plan for if you or one of your vacation pals gets sick.