This is a question that is frequently asked by many of my clients, “How do I know when I need to use hot, or cold?”
Heat is generally used to treat chronic injuries because it increases blood flow and muscle relaxation, whereas cold is used to treat acute injuries because it decreases blood flow and pain. Contrasting both hot and cold is used in the sub acute phase of healing. So what qualifies as an acute, sub acute or chronic injury? Let’s go over each stage of healing.
A hallmark sign of an acute injury is inflammation, which is the body’s immediate and necessary response to injury or tissue damage. The cause may be that you rolled your ankle, twisted the wrong way lifting an object, or had recent surgery. What happens with inflammation is your blood vessels dilate to become wider (vasodialation) and increase their permeability. This increase in blood flow and absorption allows fast delivery of nutrients and specific cells needed for tissue repair as well as efficient removal of waste products.
Signs of Inflammation
The five characteristics to help you identify the signs and symptoms of inflammation include:
4) Pain (Usually is 5 or above on a pain scale of 10)
5) Altered function, i.e. can’t move affected area due to pain, swelling
An acute injury usually lasts 48 hours, but may last up to 4 days post injury.
Why treat with Cold?
You may be asking yourself. “If inflammation is needed to help the body heal and repair itself, why stop it?” The body’s inflammatory response is often excessive in comparison to the injury. Therefore, we want to control the intensity of the inflammation to help reduce symptoms like pain.
When you apply cold to an injury your blood vessels narrow. This narrowing reduces the circulation to the area resulting in a decrease in swelling. Further, with an application of cold, the skin temperature drops which produces an analgesic/numbing effect, which helps to manage the pain.
How to treat with Cold?
To treat an acute injury apply cold to the affected area for 10-15 min. Or you can alternate 10min of ice on, 10min of ice off and repeat three times, which is often what I recommend. You can use an ice pack, frozen bag of vegetables, or ice cubes wrapped in a cloth. You will need to use a towel/cloth as a barrier between your skin and the cold application. If you are not sure how your skin will react to a cold application, it is best to check your skin after a minute or so to ensure there is no irritation.
During the cold application you will feel the following sensations.
2) Burning, tingling, or itching
Once you have reached the numb stage, the cold application has been on long enough. Also to assist with an acute injury follow the four easy steps of RICE 1) Rest, 2) Ice, 3) Compress, and 4) Elevate the area.
CAUTIONS: You should not use cold applications if you have the following:
- -Circulatory pathologies such as Raynaud’s
- -Sensory changes (i.e. decreased skin sensitivity to temperature)
- -“Cold allergy” or cold sensitivity
The subacute phase occurs around 2 days post injury and can last up to 3 weeks after. During this phase inflammation is beginning to subside, bruising changes colour to yellow, brown, or green and the area becomes less painful.
Why treat with Contrast?
Alternating hot and cold to the area causes the blood vessels to open and narrow. This action is known as a vascular flush, which helps with the healing process. This application can increase blood flow to the area by up tp 100%. When the heat is applied fresh oxygenated blood is brought to the area, which carries defensive and healing cells. When the cold is applied it reduces pain and swelling as well as build up of waste products in the cells.
How to treat with Heat & Cold
To treat with contrast therapy first apply heat to the area for 3 minutes, followed with a 1 minute application of cold. This process should be repeated 6-8 times, always ending with cold.
A chronic injury/condition is generally 3 weeks to several years post injury. It is important to note that chronic conditions may be prone to acute flare-ups in which case you would treat with ice as previously mentioned.
The following are conditions in which heat is typically helpful to relieve symptoms:
- -DOMS (Delayed onset muscle soreness) from intense work outs
- -Chronic tendonitis
- -Chronic bursitis
- -Muscle pain, spasm
- -Soft tissue contractures
- -Non-inflammatory joint pain
- -Poor mobility (helps to increase stretch and range of motion of muscles)
- -RA and other inflammatory arthritides while NOT in a flare-up period
Why treat with Heat?
Heat is an excellent way to treat chronic conditions because it increases circulation to the area and muscle relaxation, which most chronic conditions rely on for symptom relief. The increase of circulation is beneficial because it results in more oxygen and nutrient supply to the tissues needed for healing. Also, the use of heat decreases pain perception, joint stiffness, and muscle tone and spasm. Lastly, the use of heat provides a general sense of relaxation and sedation.
How do I treat with Heat?
To treat a chronic injury/condition apply heat to the affected area for approx 10min. Be sure to always place a towel between your skin and the source of heat to prevent skin irritation and burning. You can use a hot water bottle, a heating pad, or even towels that have been immersed in hot water and wrung out. If you are not sure how your skin will react to a heat application, it is best to check your skin after a minute or so to ensure there is no irritation or burns.
CAUTIONS: You should not use heat applications if you have the following:
- -Acute injury, inflamed joints, or infection
- -Existing burns
- -Circulatory pathologies
- -Sensory changes (i.e. nerve damage, or conditions such as diabetes mellitus where there may be sensory loss)