The three-layer system is a physiological response to how the body manages heat and moisture in cold, wet environments — not a marketing framework. Why age changes the calculation significantly, and what that means for a multi-generational expedition.

Why new parents, gamers, and fly fishermen all develop the same condition — the anatomy behind Mommy Thumb, Gamer's Thumb, and Fly Fisher's Wrist. Why cortisone works here when it doesn't for tennis elbow, and the treatment hierarchy that actually resolves it.