I vividly remember the first time I experienced cold weather induced asthma. It was the same day my camera froze. It was 20 degrees below zero and we were climbing two mountains in New Hampshire’s Pemigewasset Wilderness. I remember a tightness in my chest and shortness of breath. We got down ok, but I carried an inhaler for a few years after that and avoid really cold weather hikes to this day.
While cold induced asthma shares the same symptoms as chronic asthma, it’s not a chronic condition but one that is induced by exercising in cold dry weather. Called exercise-induced bronchospasm, it can be triggered during periods of heavy exertion (like climbing mountains) when people tend to breathe through their mouth instead of their nose.
Mouth breathing brings cold and dry air directly into the lungs, without the warming and moistening effect that nose breathing provides. As a result, air is moistened to only 60-70% relative humidity, while nose-breathing warms and saturates air to about 80 to 90% humidity (Source: Mayo Clinic).
Covering your mouth can help mitigate the effect of inhaling cold dry air, since an insulated buff or face mask will trap warm moist air close to your face. Breathing through a Cold Avenger Face Mask can help warm and moisten cold weather inhalations. Using a prescription Albuterol inhaler can also help when used before your hike.