Hot Packs Used in Physical Therapy

Hot packs are a type of physical modality often used in physical therapy clinics. They are applied to your injured body part by your physical therapist (PT). Physical therapists wrap moist hot packs in several layers of towels, and the hot packs are then applied directly on the exposed area that needs treatment. But why does your PT use heat, and are there risks to using hot packs during your PT treatments?

Benefits of Hot Packs

The heat provided by hot packs has several important benefits. These may include:1

Relaxes tight muscles, causing tissues to relax.Decreases pain caused by muscle tension or spasms.Causes vasodilatation of the blood vessels, which increases circulation to the area.

Increased circulation to your injured body part helps bring in nutrients, oxygen, and cells that promote healing. This increased circulation can also wash away metabolic waste materials that may be gathered around your injured body site.

Who Benefits From Using Hot Packs?

Patients with certain conditions typically benefit from using hot packs in the physical therapy clinic. These conditions may include:

ArthritisChronic painJoint contractureMuscle spasmsChronic injury where increased blood flow is desired

After an injury, heat helps to increase tissue extensibility and improve the way your muscles move.1

How Is Heat Applied?

If your PT chooses to apply heat to your body part during your PT sessions, it can be helpful to know how that process happens. That way, you’ll be prepared if you use heat in PT. Heat is applied in specific ways:

Your body should be positioned comfortablyThe body part to be treated with heat should be exposedYour PT will obtain a hot pack from a device called a hydrocollator. This is a big box containing water heated to about 160 degrees. The hot pack is filled with clay and sand, and it absorbs the hot water.The hot pack is wrapped in a terry cloth towel and applied to your body part to be treated.

When the heat is first applied, it may not feel hot; it takes a few minutes for the heat to penetrate the toweling. Just wait a few minutes and you’ll start feeling the heat penetrate your skin.

Who Should Avoid Using Hot Packs?

There are certain conditions where using moist heat and hot packs should be avoided. These may include:

In areas of impaired or altered sensitivity (like having numbness or tingling)In people with impaired mental capacityOver open woundsAfter acute injuryOver joints with acute hemarthrosisIn persons with multiple sclerosis who are sensitive to heat

How Long Should Heat Be Used?

Heat and hot packs are often applied to your body for 10 to 15 minutes. Frequent checks should be made to ensure that you are not getting too hot and to avoid skin damage. If you are getting too warm, you must remove the hot pack from your body. Using heat multiple times a day is not recommended, as it may damage your skin.