Contrast therapy is a very effective at-home self-care treatment that can really help speed up the healing process for chronic injuries.

What Is Contrast Therapy?

Contrast therapy is the application of hot and cold packs on the skin of an injured area. It decreases pain, increases circulation, and speeds healing.  Contrast therapy is most often used on sports injuries, but it is also used on chronic or repetitive injuries and injuries in the subacute stages of healing.

Contrast hydrotherapy is similar, but involves submerging the affected area in ice and heat baths.  This can be a messy and inconvenient home therapy, and it can be difficult to maintain the correct temperature in the baths in a home setting.

Contrast therapy generally consists of applying ice, then heat, then ice again in a 1:2:1 ratio.  The ratio means that you will apply the heat for twice as long as you’ve applied the ice.  You always want to end with an ice application.

How does it work?

Ice therapy flushes all the blood out of an area; this flushes away cellular debris, which speeds healing.  It also reduces pain as it numbs the area.

Heat application brings blood to the area, which has a twofold effect.  First, it (by definition) increases circulation and fills all the blood vessels in the area, down to the tiniest capillaries, with fresh blood; this reduces pain, releases tension, and reduces muscle cramping.  Second, it brings new nutrients to the area, which speeds up the healing process.

How Do I Do It?

First, let’s talk ice

Do not use a gel pack or a bag of peas!  Neither gets cold enough to have a long-lasting therapeutic effect. The area doesn’t get numb, and the pain will return in short order.  Truly numbing the area will reduce the pain for hours.

Use ice, crushed or whole, or an ice/rubbing alcohol solution.  Place it in a plastic bag.  If you don’t want the bag to leak, seal all the edges of the bag with duct tape.  An ice/rubbing alcohol solution never freezes hard and also freezes colder than ice, ideal for numbing an area quickly.  Mix one part rubbing alcohol to three parts water or ice and place in the freezer.

When icing an area, place one layer of thin cloth between the ice bag and your skin.  You don’t want anything as thick as a bath towel, as the cold won’t penetrate your skin quickly.  You also don’t want to place the ice directly on your skin, as that can result in an iceburn (similar to windburn or sunburn).  One t-shirt layer between the ice and your skin is ideal.

Again, the intention of icing an area is to numb the area.  There are 4 stages to getting numb: the area gets Cold, then it Burns, then it Aches, then it goes Numb (C-BAN). The process can be unpleasant, so let’s get it done as quickly as possible! Never ice an area for longer than 20 minutes.  If it’s not numb by then, you’re doing it wrong.

Now let’s talk heat

There are fewer tips with heat.  And by fewer, I mean one: don’t put anything on yourself hot enough to burn your skin.  Temperature varies by person; some people have “asbestos” skin that never burns, others are sensitive to heat.  If you don’t like getting hot, make sure the heat pack is small enough that it just barely covers the injured area.


  1. Ice the area until the area is numb.  Keep track of how long it takes for the area to go numb- no longer than 20 minutes!  Usually around 10 minutes.
  2. Use mild to moderate heat to bring blood and nutrients back into the area.  Heat the area for twice as long as you iced the area; usually around 20 minutes.
  3. Ice the area again.  Usually around 10 minutes.
  4. Repeat as desired or needed.  Once per day is generally advised, but always refer to your doctor or physical therapist’s advice on frequency.

When Should I Avoid Contrast Therapy?

Contrast therapy is helpful in a wide array of applications.  However, there are a few instances in which contrast therapy should not be used.

  • Contrast therapy should not be used on an acute injury.  If:
    • your injury occurred zero to four days ago
    • there is inflammation (heat & redness) or swelling in the area
      then your injury is acute and is best treated with ice alone, and not contrast therapy.
  • If the skin in the area is compromised, then do not use contrast therapy.  This includes
    • cuts
    • scrapes
    • burns, including sunburns!
    • boils
    • cysts
  • If you have peripheral neuropathy, then proceed with extreme caution.  You may not know if your skin is being damaged.  Check under any hot or cold pack very often, and discontinue therapy immediately if the skin turns dark red or swells.

Troubleshooting and FAQs

What if my skin turns bright red?

This is normal.  If your skin turns dark red, you are burning yourself.  This can happen with either the heat or cold application, so please pay attention, especially if you are new to using contrast therapy at home!

How do I know if it’s working?

It is normal for the pain of an injury to return after several hours, especially after your first or second treatment.  With subsequent treatments, the pain should decrease in both severity and frequency.

Remember, the key to contrast therapy is perseverance.  Keep using it until your injury is completely healed!

If you see no improvement after two or three sessions, and you’ve followed all these instructions, then it would be best to discontinue contrast therapy, and to discuss further treatment options with your doctor or physical therapist.

Contrast Therapy