Most foot trouble starts with the sock.

You spend on the boots and the pack. Then a thin, sweat-soaked sock bunches at the heel three miles in, and the day turns into a count-down to taking your shoes off.

Hot spots, blisters, cold toes, and that damp, slipping feeling — almost all of it traces back to the one layer between your foot and the trail. Get that layer right and everything above it works better.

Damp, then cold

Cotton holds sweat against the skin. Once it's wet, it stays wet — and cold.

Bunching & slip

A sock without a real arch hold migrates, folds, and rubs exactly where you don't want it.

Hot spots & blisters

Thin fabric and seams in the wrong place turn friction into a blister by lunchtime.

Worn through fast

The cheap pair thins at the heel and toe within a season. You buy again, and again.

Merino is a fine, soft wool from merino sheep. It does four things ordinary cotton and synthetics can't do all at once — which is exactly what a foot needs over a long day.

• 1

  Stay-put cuff

  A ribbed top grips the calf so the sock never sags into your boot.

• 2

  Arch lock band

  A band of stretch through the midfoot holds the sock in place — no bunching, no slip.

• 3

  Cushioned heel & toe

  Extra-dense knit pads the two spots that take the most impact and the most wear.

• 4

  Smooth toe seam

  A low-profile seam across the toes removes the ridge that starts most blisters.

• 5

  Breathable instep

  A lighter mesh-knit panel over the top of the foot dumps heat on the climbs.