Here is an explanation of how cold and warmth work with the body. This will help you understand when to use ice packs and when to use warm compresses.

Dr. Greene’s Answer:

Great question. Many parents and teachers ask the same question. Below is an explanation of how cold and warmth work with the body. I hope this will help you understand when to use ice packs and when to use warm compresses. I’m also including a few tips to make it easier to treat an injury. By the way, don’t forget to “kiss it” to make the boo-boo better. Studies show that aids healing, too.

Ways Cold Can Help

Ice (or cold compresses) can help, in at least five ways.

    1. It can help prevent swelling to an injured area
    2. It can reduce bleeding
    3. It can reduce inflammation (reducing delayed injury)
    4. It can temporarily reduce pain
    5. Increased blood flow. When the cold compress is removed, you may have noticed the area underneath remains reddened for a while. This redness is increased blood flow, bringing elements to speed healing to the site of the injury. You get increased blood flow without increased metabolism – ideal for healing.

Best Icing Practices

Ice or cold compresses can also cause injury if not done right: too cold or too long.

Ice cubes themselves, right from the freezer can be too cold. Ice in a Baggie with some water stays at a constant 32 degrees as the ice melts, pretty ideal.

Frozen gel packs can be even better and more convenient, but some get cold enough to cause frostbite if applied directly on the skin for too long. It shouldn’t hurt.

I like 20-minute cold compresses for kids. The numbness kicks in after about 5 minutes and the increased blood flow kicks in after 12-15 minutes: and can continue more than 50 minutes after the compress is off (longer than with warm compresses).

Applying a cold compress longer than 25-30 minutes is too long.

Several times a day is fine. 3 or 4 is probably the max that help speed healing, but up to every hour is fine for comfort.

Another Cool Way to Do Cold: Ice Massage

Apply an ice cube directly to the injured area, but keep it moving, rubbing the skin. The melting and movement keeps it from getting too cold.

The big advantage is you get the fastest neural pain relief: average of only 1 minute 45 seconds when studied. Plus some kids feel comfort from the rubbing touch right away. Ice massage should only be done for 10 minutes at a time, with at least a 10-minute break in between.

Disadvantage? You don’t get the long afterglow of a 20-minute compress. The numbness starts to wear off just a few minutes after stopping.

I enjoy one 10-minute massage followed by a 10-minute break and then a 20-minute cold compress for lasting relief.

When is Warm Better?

Warm compresses can be great too, in the right setting.

If and when swelling or bleeding is not (or no longer is) an issue after an injury, warm compresses can be very soothing and also increase blood flow.

Warm compresses are especially good if there is tightness or spasm.

There is something utterly comforting about warmth, so if comfort is the bigger issue than speeding healing, I’ll often go straight to warm.

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Alan Greene MD contributor