Ask a PT Response: "When was your knee replacement? It is generally not recommended to utilize a hot pack during the period immediately following a knee replacement as this could result in an increase in edema/inflammation. A ice pack is more commonly utilized to assist with decreasing pain and edema immediately following surgery. As far as your question in regards to using a hot pack at the knee with existing conditions such as CAD, CHF and DM; hot pack use is generally not a contraindication unless there are issues with impaired sensation, recent or potential hemorrhage, infection, malignancy, or thrombophebitis. For further clarification, it may be a good idea to consult with your surgeon to make sure a hot pack can be utilized."