| What it is | Fluid pocket from friction |
| Made worse by | Moisture, heat, poor fit |
| Early warning | 'Hot spot' (warm, red, tender) |
| Key | Treat the hot spot before it blisters |
A blister is a fluid-filled pocket that forms when repeated friction, often worsened by moisture and heat, separates layers of skin — the most common hiking injury. It’s preceded by a ‘hot spot,’ a warm, reddened, tender patch; treating that hot spot immediately with tape or a patch usually prevents the blister from forming.
This is general educational information, not medical advice.
Prevention
Well-fitted, broken-in hiking boots, wicking socks, and dry feet are key; a foot-care kit belongs in your Ten Essentials.
Frequently asked questions
What causes blisters when hiking?
Friction — skin rubbing repeatedly against socks or footwear — is the root cause, made worse by moisture (sweat or wet feet), heat, ill-fitting or new boots, wrinkled socks, and grit. The rubbing separates skin layers and fluid fills the gap, forming a blister, usually on heels, toes, or the balls of the feet.
How do you prevent blisters?
Wear well-fitted, broken-in footwear and moisture-wicking (non-cotton) socks, keep feet dry, address rubbing immediately, and use preventive tape, lubricants, or double-layer/liner socks on known trouble spots. Most importantly, stop and treat any 'hot spot' the moment you feel it, before it becomes a blister.
Should you pop a blister?
If it's small and not too painful, leave it intact — the skin protects against infection — and cover it with a padded dressing or blister bandage. If it's large, painful, or likely to burst, it can be carefully drained with a sterilized needle at the edge while leaving the roof of skin on, then cleaned and dressed. Watch for signs of infection.
Sources
- Foot care — American Hiking Society
- Blister management — Wilderness Medical Society