Mechanism & Pathophsiology
Carbon monoxide (CO) is colorless, odorless, tasteless, and initially non-irritating; signs and symptoms of CO poisoning are delayed and often accumulative. CO binds to hemoglobin on red blood cells and is carried as carboxyhemoglobin (COHb) in the blood. Bound CO prevents oxygen uptake by hemoglobin and significantly reduces the blood's oxygen carrying capacity. CO also binds to other molecules in the body and reduces the function of all high oxygen-demand organs (heart, brains, & lungs) even after the CO has been cleared from the blood. In a wilderness environment, CO is typically generated as a byproduct of incomplete fuel combustion in a stove or lantern. Signs and symptoms of CO poisoning vary widely based on exposure level, duration, and the general health and age of an individual.
(How to avoid, and if necessary treat, dry, chapped, and cracked skin on an outdoor trip.)
The skin is the largest organ of the body; it varies greatly in thickness offering both physical protection from minor traumatic injury and denying access to potentially dangerous microorganisms. The outer layer of the skin (epidermis) is extremely tough and contains melanin while the more sensitive underlying layers—dermis and subcutaneous tissue (or hypodermis)—contain blood vessels, nerve endings, subcutaneous fat, and connective tissue. The skin on your hands and feet is much thicker than the skin on the rest of your body, and therefore tougher; it can take up to six months for severely chapped hands and feet to heal sufficiently and regain its barrier strength. Aside from your lips (a notable and important exception), your skin contains melanin to help protect it from excessive ultraviolet (UV) radiation and has glands that excrete water, electrolytes, and oils. Blood vessels within the skin layers aid in thermoregulation as they contract to conserve heat or dilate to release it. Sensory nerves transmit environmental messages to the brain.
Winter is here...and in many places it brings snow to the mountains. Lots of it. And with lots of mountain snow comes avalanches. Some of them are fatal.
As a former ski patroller and an avid back country skier, I'm familiar with avalanches. I've watched friends go for rides, recovered bodies, and even been fully buried myself. I have lots of stories. When I was caught and buried we did all the "right" stuff (dug multiple pits, were familiar with the snowpack and terrain, cut the hill numerous times) but none-the-less I got caught. It was a wild and scary ride. I'm quite glad my friend was well trained, had years of rescue experience, and there to dig me out. Although I managed to create a small air hole with my left hand before the snow completely settled, I don't think I could have gotten free by myself. I lost some gear, broke a brand new ski (it could easily have been my leg), and gained increased respect for the power of sliding snow. Later that winter I overheard a ski buddy with years of ski guiding, patrolling, and avy control experience say to a new backcountry skier: "If you spend enough time skiing in the high mountains, you'll eventually get caught in a sluff or avalanche." Whoa! Not particularly reassuring, yet I've found it to be true....
Our public YouTube channel has educational and reference videos for many of the skills taught during our courses. Check it out!