Most of us grew up hearing “Put some ice on it!” after any injury from either a coach, parent, or doctor – and they weren’t wrong! Ice can definitely help after certain injuries. However, there are circumstances that heat may be more of effective than ice.
As physical therapists, one of the most common questions we get from our patients is “Should I use ice or heat?” and there is a science behind it.
What does ice do?
After suffering a sprained ankle at soccer, ice is the better answer. Ice as a treatment method should be used for what are known as acute injuries (injuries that occur suddenly such as a sprain) or chronic conditions (injuries that last over three months such as tendinitis). When used correctly, ice helps to reduce swelling which in turns helps to decrease & control the pain around the injury site. Ice can also be used to reduce muscle spasms.
When ice is applied to an area, the body responds by tightening the blood vessels (vasoconstriction). When the bloods vessels tighten, the amount of blood that can flow to the area is reduced leading to a reduction in the swelling of the site. As the cold begins to travel through the skin and into the tissue underneath the outer layer of skin, cellular activity is slowed down. When cellular activity slows down, cell death & cell division is reduced resulting in less pain & inflammation.
When to use ice
If you suffer one of the following injuries, ice can be effective:
Carpal tunnel syndrome
IT band syndrome
How to use ice
It sounds like using ice should be self-explanatory, however there are some things to know.
Don’t ice for more than 10-15 minutes. There is no added benefit after the 10-15 minute time frame.
Don’t ice an hour before activity. Icing too soon before activity can result in injury.
Ice after activity, especially if you suffer from overuse injuries like tendinitis. Keep the swelling and inflammation under control by routinely icing after you are finished with your activity.
Wait at least 2 hours before icing again. Allow your body to return to normal temperature before reapplying.
If you have an open cut, be sure to use something to separate the ice from the opening. Putting ice directly on an opening can result in infection.
If you are sensitive to ice/heat, use something to separate your skin from direct contact.
What does heat do?
In instances where you are feeling tight, achy, or stiff, heat is the answer.
Heat stimulates the blood flow to a certain area and therefore should not be used where swelling is present (swelling is caused by bleeding into the tissue & heat would cause more blood to flow to the area). Where ice constricts the blood vessels, heat does just the opposite. It allows the blood vessels to expand which in turn allows the muscles to relax. Further, when heat is applied, it stimulates circulation which promotes pain relief (some people refer to this as a “soothing” effect).
When should you use heat?
Heat is best used for pain & conditions referred to as chronic (or pain that reoccurs frequently). Some examples of injuries/conditions that heat should be used for include:
Lower back pain
Poor blood circulation
Tension in your neck
How to use heat
Similar to ice, there are some things to know before applying heat:
If you are experiencing numbness, do not apply heat.
If you have a fever or are suffering from heat stress, do not apply heat.
Only use heat for 10-20 minutes at a time. Heat over an extended period of time can cause the burns. Please note: this means do not sleep with heat on.
For both heat and ice, be sure to access your skin after using either. Some redness from either is completely normal, but nothing that causes pain or burning.
Ice and heat are not meant to be used as a treatment method, but can be used as part of your treatment regime.
If you are unsure which you should be using or have a serious medical condition, contact your doctor or physical therapist to get their opinion. Otherwise, try one and if you don’t get any relief, try the other!