Effective ReliefWhen to use Recommended for the relief of muscular pains and stiffness including back and rheumatic pain, sciatica, fibrositis, sprains and chilblains. Can be used before or after exercise.How it works Deep Heat generates penetrating warmth in aching, injured and sore muscles. Deep Heat Heat Rub can be used before or after exercise and contains ingredients that provide pain-relief plus heat. Heat therapy helps to increase blood supply to relax and soothe.