Hot packs are a form of heat therapy. It works works by improving circulation and blood flow to the applied area, due to increased temperature. Even a slight increase in temperature of an injured area can soothe discomfort and increase muscle flexibility.
Types of Heat
There are two different types of heat therapy: dry heat and moist heat. Both aim for to reach a “warm” stage as the ideal temperature, vs “hot.”
- Dry heat (or “conducted heat therapy”) includes:
- Heating pads
- Dry heating packs
- Moist heat (or “convection heat”) includes:
- Steamed towels
- Moist heating packs
- Hot baths
When applying heat therapy, you can choose to use local, regional, or a whole body treatment. Local therapy is best for small areas of pain, like a stiff muscle. You could use small heated gel packs or a hot water bottle to treat an injury locally. Regional treatment is best for more widespread pain or stiffness, and could be achieved with a steamed towel, large heating pad, or heat wraps. Full body treatments would include options like saunas or a hot bath.
There are certain cases where heat therapy should not be used. If the area in question is either bruised or swollen (or both), it may be better to use cold therapy. Heat therapy should never be applied to an open wound.
People with certain pre-existing conditions should not use heat therapy due to higher risk of burns or complications due to heat application. These conditions include:
- Vascular diseases
- Deep vein thrombosis
- Multiple sclerosis (MS)
If you have either heart disease or hypertension, ask your doctor before using heat therapy. If you are pregnant, check with your doctor before using saunas or hot tubs.
How Long Should I use Heat?
If you are using heat due to minor stiffness or tension, the heat source can relieve pain in as little as 15 to 20 minutes of heat therapy. For moderate to severe pain, longer sessions may be more beneficial. For example, taking a warm bath, lasting between 30 minutes and two hours.