Cryotherapy, or the application of ice/cold packs, is a simple and time-proven modality to reduce pain and to treat injuries. It’s used worldwide thanks to its effectiveness, convenience, low cost and ease of use. Cryotherapy is believed to reduce pain by initiating local anaesthesia over the area it is placed.Cryotherapy is also used to decrease localized edema, inflammation, nerve conduction velocities, and local blood flow. The effects of therapeutic cryotherapy mainly depend on the method used and the temperature of the ice/ice pack used, the duration and the depth of the subcutaneous fat.Heat therapy, or the use of hot packs, is used as a therapeutic intervention to decrease pain in joints, muscles and other soft tissues, increase blood flow, and improve connective tissue extensibility. Heat therapy can also increase oxygen uptake of local tissues and accelerate tissue healing. Care should always be taken with using heat therapy too soon after an acute injury, as it can worsen swelling and inflammation.Physical Therapists routinely use both cryotherapy and heat therapy in the clinic to treat a wide range of conditions. These conditions range from acute tissue injuries, such as muscle and joint sprains, myofascial trigger point release, tendinitis, acute localized swelling after injuries, bursitis, and many more. Both cryotherapy and heat therapy should be used with proper care in the home and clinic to prevent any ice or heat burns from over prolonged use. When used correctly both modalities are safe, convenient and effective methods for pain relief and other intended uses.