Blisters are the most common injury on long hikes, and they are also one of the most preventable. A blister forms when repeated friction separates layers of skin and fluid fills the gap, usually on the heel, the ball of the foot, or between toes. The warning sign is a hot spot: a warm, reddened patch that feels sore before any blister appears. Treating a hot spot immediately takes a minute. Treating a full blister takes much longer and can end a multi-day walk. Learning the difference is one of the most useful skills a hiker can have.

Prevention starts before the hike. Wear boots or shoes that fit well and are broken in, and choose socks that wick moisture and fit without wrinkles. Many long-distance hikers wear a thin liner sock under a thicker hiking sock to reduce friction. Keep feet dry by changing socks at lunch stops on long days, and air your feet whenever you stop. Apply tape or a blister patch to any spot that has caused trouble before, rather than waiting for it to hurt again. Lubricants and foot powders help some hikers, but they are no substitute for good fit.

When you feel a hot spot, stop right away. Sit down, take off the shoe and sock, and let the foot cool and dry for a few minutes. Apply a piece of smooth tape, moleskin, or a blister plaster over the area, smoothing it flat so no edge can roll and cause more friction. If the problem is a wrinkle in the sock or a small stone in the shoe, fix that too. Most hikers resist stopping for such a small thing, but the few minutes it takes are nothing compared with the pain of a blister the next morning.

If a blister has already formed, decide whether to drain it. Small, intact blisters that are not very painful are best left alone and protected with a padded dressing. A large, painful blister that makes walking difficult can be drained carefully: clean the area and your hands, sterilise a needle with a flame or alcohol, make a tiny hole at the edge of the blister, and press the fluid out gently while keeping the overlying skin in place. That skin is a natural bandage that protects against infection. Cover it with an antiseptic dressing and tape, and check it daily.

Watch for signs of infection, which need prompt attention: spreading redness, increasing pain, warmth, swelling, or any discharge. If these appear, clean the area thoroughly, keep it covered, and seek medical help if the symptoms worsen or you develop a fever. Never cut away the skin over a blister, and never apply treatments you have not used before to broken skin on a long hike. If a blister makes walking genuinely painful despite treatment, take a rest day. Pushing on can turn a minor injury into one that ends the whole trip.

After the hike, let blisters heal with air and clean dressings, and think about what caused them. Was it the footwear, the socks, wet conditions, or a pack that was too heavy? Adjust one thing at a time before the next trip. Feet adapt over time, and hikers who look after their feet from the first hot spot onwards finish long trails with far fewer problems. Treat your feet like the most important piece of gear you own, because on a long hike, they are.

One more preventive habit is worth adding to your routine: inspect your feet every evening on a multi-day hike. Wash them, dry them thoroughly, and check for redness, swelling, or early hot spots. Treat anything you find before bed, so it heals overnight instead of worsening on the next day of walking. A few minutes of foot care each evening is a small price for finishing a long hike comfortably, and experienced hikers treat it as non-negotiable as pitching the tent or filtering water.