Frostbite during mountain climbing or outdoor activities often occurs when people are not paying attention. Areas affected by frostbite frequently become numb due to the cold-induced constriction of blood vessels and poor blood circulation. Experienced individuals consciously wiggle their toes and fingers, and take immediate action to warm up numb limbs as soon as they feel any numbness—placing hands or feet against their own or a companion’s body if necessary. Hypoxia reduces the body's metabolic rate, and dehydration thickens the blood; both factors make frostbite more likely. Exposed skin can suffer frostbite in less than a minute when exposed to wind. Newly frostbitten tissue appears white (due to lack of blood) or purple-red (due to blood stasis) and feels hard. Companions should frequently check each other for signs of frostbite.
For severe frostbite (assuming there is no risk of refreezing), the treatment involves immersing the frostbitten limb in warm water at 40°C to 43°C to thaw it. Restoring blood circulation to the affected area is the primary goal of treatment. Minor frostbite can be treated by placing the hands or feet inside warm undergarments. Feeling pain is a good sign. Be aware that thawed tissue is very sensitive and fragile; refreezing thawed tissue can cause more damage than leaving it frozen initially. Therefore, if the injured person needs to walk down using frostbitten feet, or if the frostbitten area might freeze again during evacuation, it’s better not to thaw it yet. Taking aspirin can help dilute the blood and promote circulation. After initial first aid and before seeing an experienced doctor, the main concern is preventing infection. Oral antibiotics may not reach the wound effectively due to poor blood circulation.
Many tissues severely damaged by frostbite do not regenerate. Regrowing tissue is very difficult without proper blood supply. To prevent further damage to the rest of the body, doctors often have no choice but to recommend surgical removal or amputation.
People living in cold environments develop physiological responses to cold over time—such as increasing blood flow to the skin’s surface—which improves their resistance to the cold. Those who regularly swim in winter or take cold showers are familiar with this. The old saying “bundle up in spring and tough it out in autumn” reflects this principle. In contrast, those who grow up in warm environments often lack basic habits and awareness of cold protection. People from northern regions learn from childhood experiences like snowball fights what it feels like to have numb hands from the cold, the tingling or painful sensation when warming up, and temporary measures to cope when the wind is biting and clothing is inadequate. Those with little experience in cold climates often don’t know many practices that locals take for granted. I don’t know how much experience Chen Junwu had with sub-zero temperatures before, but I’ve noticed that people coming from southern, warmer climates often have no idea how to dress effectively for winter when they first arrive in the north.
Generally speaking, mittens are much warmer than gloves with separate fingers. I usually wear very thin, non-absorbent polypropylene gloves underneath. They’re useful when you need finger dexterity for short periods. The outer gloves should be attached with a string and hung around your neck. It may look silly, but not as silly as having your gloves blown away by the wind.
This also highlights the importance of gradual acclimatization in mountaineering and outdoor activities. Many skills are acquired slowly over time. Even something as minor as choosing and wearing gloves can lead to lifelong disability.