Stop at the hot spot
A hot spot is a blister that has not formed yet. It feels like a small warm patch, usually on the heel, the ball of the foot, or the side of a toe. Stop within 5 minutes of noticing it. Every minute you keep walking makes the patch bigger.
A common mistake is ignoring one because the group is behind schedule. By the time you stop, the hot spot has become a 3-centimeter blister and the next two days are miserable.
Clean, dry, then tape
Take the boot and sock off. Dry the skin completely, including between the toes. A dressing will not stick to damp skin, and a loose patch rubs harder than no patch at all.
For an intact hot spot, a single layer of thin adhesive tape or moleskin works well. Cut it 1 centimeter wider than the red area on every side, and round the corners so they do not lift. Press it down for 20 seconds; body heat helps it set.
- Thin adhesive tape: stays put when wet and works well for prevention.
- Moleskin: thicker, good for a formed blister with a donut cutout.
- Hydrocolloid patch: cushions and stays on for a day or two.
- Blister powder or antiperspirant: useful before the hike, not after.
Draining a blister
If the blister is large and painful, drainage helps. Clean a needle with alcohol or a lighter flame, pierce the edge of the blister in two places, and press the fluid out with a clean gauze pad. Do not remove the roof of the blister; it is the best bandage you have.
Cover the drained blister with a hydrocolloid patch or a gauze pad and tape. Change it at the end of the day and check for redness spreading beyond the edge, which can signal infection.
Prevention that actually works
Blisters come from three things: moisture, friction and fit. Fix the fit first. A boot with a loose heel will rub no matter what tape you use, and lacing the top two eyelets tighter often solves it.
Change socks at lunch if your feet are damp. Thin wool socks dry faster than cotton and cause fewer problems. On long days with water crossings, carry a dry pair in a zip bag and swap at the halfway point, then air the wet pair on the outside of the pack.
When to call it
Turn around if the blister is on a weight-bearing point, is bleeding, or the skin around it is hot and spreading. Walking on an infected blister for another 15 kilometers turns a day off into a hospital visit.
For the walk out, pad generously and slow down. If you are still hours from the car, treat it, shorten the stride, and skip the side trip you had planned. A short day with a treated foot beats a long day that ends with a limp.
