John Lewis Heat Generating Ribbed Thermal Leggings, Grey at John

These heat retaining and heat generating thermal leggings will be a life saver during the winter months.

Heat is generated using the body's moisture and the warmth is retained through a snug, comfortable fit. They'll feel super soft and lightweight on the skin, so you can layer over them.

The stretchy, ribbed leggings are quick drying, anti-static and naturally breathable.