Pants, long-sleeve shirts and skirted hats also provide protection against another backcountry assailant: the sun. Sun-blocking lotions also work well if applied liberally and regularly. Many flatlanders underestimate the intensity of sunlight at high altitudes, particularly if snowfields are adding their reflection to the glare. When I was embarking on an expedition to McKinley in 1982, my assistant, who was quite pale after the long, dark, Alaskan winter, told me she hoped to come back with a gorgeous tan. I told her, "If you do the absolute best you can to protect yourself, you'll come back with a tan. If you do any less, you'll come back peeling like weathered paint."
Blisters rank with mosquitoes and sunburn as the miseries that beset backpackers most often. The first defense, of course, is properly fitting boots. The second is to avoid boots that are stiffer than you really need. If you need stout boots because you’ll be packing a heavy load, be sure to break them in thoroughly by wearing them around town, then on progressively longer day hikes.
If a hot spot does start to develop, stop and deal with it immediately, before it erupts into a full-fledged blister. Sometimes the problem can be fixed simply by straightening out a wrinkled sock. On long, steady downhills, it can help to lace your boots extra tight to prevent your feet from sliding forward at each step, thereby blistering the soles and toes. Wearing a thin pair of socks under a thicker pair can also help. If these tactics fail, I employ moleskin, an adhesive-backed felt-like material found in nearly all drugstores. I usually slap a piece of moleskin directly over the hot spot and leave it there for the duration of the trip. If a pair of boots frequently gives me trouble in the same spot, I'll counterpunch by applying moleskin before starting the hike. Don't forget to bring a knife, preferably one with scissors, to cut the sheets of moleskin to the right size; you can't tear it easily as you can adhesive tape.
If a blister does develop, cover it with something that won't stick to the blister itself, like an adhesive bandage or a piece of moleskin reversed so that the sticky side faces away from your skin. Once you've protected the blister, cover the area with moleskin or tape to keep the protective layer in place.