When you are injured, or when you experience soreness or chronic pain, you may receive conflicting advice about what to do. Should you apply heat? Apply cold? Below is an overview of how to effectively use temperature in the healing process.
What is a cold pack?
Cold packs include blue gel packs that are kept in the freezer, coolant bags that become cold when you punch them so you don’t need to keep in the freezer, and self-made cold packs that can be constructed from a zip-lock filled with crushed ice and a bit of water with the air taken out and then wrapped in a damp towel.
When should you use a cold pack?
Cold therapy can help individuals that are experiencing acute injuries like ankle sprains, muscle or tendon strains, swollen areas or bruising.
How does a cold pack work?
When damage occurs in soft tissue, such as muscle tearing, blood vessels may rupture within the muscle and the injury site begins to bleed internally. This increase in blood volume in the area can cause cell death by what is known as secondary hypoxic injury. Thus, every effort should be made to control excessive bleeding. Following this, the human body’s response to injury is to start the repair process immediately by protecting the damaged tissue (by increasing pain and swelling) and producing a fluid called exudate fluid that carries all the cells and chemicals in the area to repair the damaged tissue (the body’s own type of emergency service). Damaged cells release a chemical that starts this process, and it is essential for healing. If this can be limited then recovery times will be shorter. This process is called inflammation and is vital to tissue healing.
Cold packs are very effective at reducing swelling and numbing pain. An injury swells because fluid leaks from blood vessels; cold causes vessels to constrict, reducing their tendency to ooze. The less fluid that leaks from the blood vessels, the less swelling results. Cold also eases inflammation and muscle spasms – two common sources of pain.
The sooner you apply an ice pack to a sprain or strain, the sooner it can do its job to reduce pain and swelling. For chronic problems such as low back pain or muscle spasms, a cold pack should be applied whenever the symptoms start up.
How long should you use a cold pack for?
Apply cold packs for periods of up to 15 minutes, 2-3 times per day. Do not leave the ice on for more than 15 minutes as you could cause an “ice burn”. Take additional precautions when using cold packs if you suffer from any of the following conditions:
- Hypersensitivity to cold or cold intolerance
- Paroxysmal cold hemoglobinuria
- Raynaud’s Disease
- Syncope/Cold allergy
- Over regenerating peripheral nerve
- Poor circulation/PVD
- Angina pectoris/cardiac dysfunction/respiratory complications (avoid generalized cold)
When should you use a heat pack?
Heat packs are used to alleviate the symptoms of chronic pain and sore or tight muscles (i.e. pain in the neck or lower back).
How does a heat pack work?
Heat can increase blood flow and help to restore movement to injured tissue. Warmth can also reduce joint stiffness, pain, and muscle spasms. Apply a heat pack for periods of up to 20-30 minutes, 1-2 times per day. Take additional precautions when using heat packs if any of the following conditions apply:
- Over areas of impaired sensation
- Pregnancy (avoid generalized heating – no heat pack on abdomen or Jacuzzi)
- Poor thermoregulation (very young or very old)
- Cardiac insufficiency (avoid generalized heating)
- Over open wounds
- Impaired cognition
- Over areas where topical counterirritants have been recently applied
When should you switch from a cold pack to a heat pack?
Observe by ‘Pain-Swelling-Redness-Hot.’ If you still have these four symptoms together, you apply cold to the affected area. If you have just one of the symptoms and it’s been more than 3 days, you apply heat:
- Pain – feel pain
- Swelling – touch around and compare to other side
- Redness – look red just only that area
- Hot – touch around and compare to other side
In addition to the ‘Pain Swelling Redness Hot’ approach, you can also apply “PRICE,” which should be carried out as early as possible after injury and continued for a minimum of 24-72 hours:
- P = Protection (i.e. support, taping)
- R = Rest – This does not only refer to the prolonged period of time that the athlete will be out of action, but also to the immediate period after the injury. There are a number of different degrees of rest and this depends on the severity of the injury and the type of tissue damaged.
- I = Ice – Usually applied to the injured site by means of a zip-lock filled with crushed ice which is then wrapped in a damp towel for 15 minutes.
- C = Compression – Wrap it up.
- E = Elevation – Allows gravity to drain the fluid away from the injured site. This aids in decreasing the swelling, which in turn may decrease the pain associated with the swelling.
This principle plays an important role in limiting swelling and decreasing pain around the injury and therefore speeding up the healing process.
Perseverance is key to effective hot/cold therapy. If you’re seeing benefits, keep up the treatments until you are fully healed. Get better soon!
Ms. Rattikarn Kaewkajohn (Maprang) A physiotherapist who has a passion for sports and exercises. Maprang graduated from Thammasat University, Allied Health Science Faculty