Illustration: Kieran Blakey

The Nuance

‘Biofeedback’ Could Ease Headaches, Anxiety — and Maybe a Lot Else

By providing a window onto the body’s inner workings, biofeedback could help people control what was once thought to be ungovernable

The man’s boasts were outlandish. Wim Hof, a 51-year-old Dutch endurance athlete…