NOLS students of the 60’s and 70’s will remember Paul Petzoldt’s advice to lace their stiff, heavy, leather hiking boots loosely. This technique required a deliberate, well-placed, flatfooted walking technique that helped avoid blisters and sprained ankles.

Layers of skin rubbing against each other or the inside of the boot can cause an irritation known as a “hot spot.” If the skin layers separate and fill with fluid, a blister may form. These simple injuries can be the source of profound discomfort and occasionally a trip-ending evacuation.

The key is prevention

It is easier to stay warm than to warm a hypothermic person, and it’s easier to prevent, rather than treat, blisters.

Blisters are a leadership challenge before they are a medical problem. Whether you are leading yourself or leading others, model stopping and checking your feet. It sends a powerful message when team members see their leader take the time to look at their feet, change their socks and deal with irritations before they are blisters.

Blisters don’t happen without warning. As soon as you feel irritation or pain, stop. We’ve all probably used the excuse that we didn’t want to delay the group. We may have thought we could wait until the next rest break. Unfortunately by the time we stop, the hot spot may be a blister, and a small problem has become a challenge to manage. It’s good expedition behavior to speak up and ask for time to care for your feet.

Keep your feet dry. Wet, hot skin blisters faster than cool, dry skin. Wear a liner sock to wick moisture away from your foot—polypropylene, wool or wool-nylon blends work well. Change from damp sweaty socks to dry socks in the middle of the day. Dry your feet at rest breaks.

While it helps to have your boots broken in, first they must fit. This was critical in the days when only heavy leather boots were available, but it’s still important in this age of lightweight boots. Keep in mind that your feet swell during the day, sometimes an entire size. Thus, buy your boots in the afternoon. Match your fit to the socks you plan to wear. Your toes should be able to wiggle, but not hit the front of the boot when you walk downhill.

You socks should be wrinkle-free. Gaitors help keep dirt and debris from irritating your feet.

Know your vulnerable spots, like the back of your heel or the ball of your foot. Pad these early. Moleskin is the gold standard. People also use duct and athletic tape. Be careful you don’t develop a blister under the tape, which may turn into a painful open blister when the tape is removed.

Athletes will use lubricating agents (mineral oil, silicone fluids, petroleum jelly, and glycerin to name a few), antiperspirants and drying powders over skin vulnerable to blistering. While it’s logical to assume these substances could help prevent blisters by keeping feet dry and reducing friction, the military, which has done a lot of testing on blister prevention, hasn’t found them to be the magic bullet against blisters.

Treatment

There are many different techniques for hot spot and blister care. Each has acolytes who proselytize their methods around the wilderness campfire. The following are tried and true over years of NOLS expeditions.

Hot Spots. If it’s still only an irritation, pad it with moleskin as a buffer against further rubbing.

Small Blisters. If a small blister has already developed, cut out a doughnut-shaped piece of molefoam and center it over the blister. The doughnut "hole" prevents the adhesive from sticking to the tender blister and ripping it away when the molefoam is changed.

Larger Blisters. If the blister is nickel-sized or larger, drain it. Clean the area around the blister to decrease the risk of infection. Use a needle that has been soaked in an antiseptic solution or has been heated until it glows red, then cooled. Insert the needle at the base of the blister, allowing the fluid to drain from the pinprick. After draining the blister, apply an antibiotic ointment and cover the area with gauze. Center a doughnut-shaped piece of molefoam over the drained blister and gauze. Follow up by checking the blister every day for signs of infection.