NEW! Kevin Murphy Heated Defense Leave in Heat Protection 5.1 oz. Protect your hair against daily life's biggest aggressor, heat damage. Heated Defense is a weightless and invisible leave-in treatment foam to protect your hair against damage associated with heated and mechanical tools. Providing heat protection up to 232˚C / 450˚F, this leave-in foam distributes easily and disappears in all hair types, providing a weightless protective shield.