Muscles that burn energy without contracting have yielded new clues about how the body retains a constant temperature – and they may provide new targets for combating obesity. Traditionally, the body’s main thermostat was thought to be brown fat. It raids the body’s white fat stores in cold conditions to burn energy and keep the body warm. Muscles also play a role in keeping the body warm by contracting and triggering the shiver response – but this is only a short-term fix because prolonged shivering damages muscles. Now it seems that muscles have another way to turn up the heat.
