The first thing to consider is whether to use local or systemic heating.
Local heating is applying specific, localized heat to an area. Examples of local heating are; hot water bottle, wheat bag and heat gels.
Systemic heating is applying heat to the whole body. This includes things like; a hot bath, spa pools or a hot shower.
Both of these approaches are good, what is best will depend on your goals for using the heat. For example, if you are achy all over from poor posture at work, systemic heat may be the way to go. Alternatively, if you have a specific tight muscle that you want to ease, local heating will be better.
Moist heat Vs Dry heat
The next decision to make is whether you use moist heat or dry heat.
Dry heat draws moisture out of the skin. One advantage of dry heat is that can be easier to use and can be convenient. A disadvantage is that it can dehydrate the skin. Common dry heat sources are electric heat pads and Infrared heat lamps.
Moist heat sources are things like steam towels, hot baths, hot water bottles and wheat bags. This type of heat is less likely to dry the skin out. Generally, moist heat is preferred over dry heat as it is likely to penetrate deeper and faster than dry heat. One study found that moist heat had enhanced benefits over dry heat with only 25% of the application time of dry heat.
Are creams that “heat” an area, such as Deep heat or tiger balm, any good?
These types of creams feel hot but do not necessarily heat the area. They do dilate superficial capillaries of the skin, but the term “deep” heat is bit of an oxymoron. It is only superficial.
These types of creams have chemical irritants called rubefacients. These are chemicals that create mild chemical burns on the skin that cause redness of the skin due to dilation of superficial capillaries. Capsaicin is a common rubefacient. This is the chemical that makes chili’s “hot”. Authors from one study found that “Chemicals that are mild skin irritants may make a patient feel warm, but they will not produce any in vivo temperature rises or any physiological effects of heat”.
It is thought that these types of creams may make you feel better since they act as a neurological distraction from your pain. In other words, they take your mind off the pain.
How deep does the heat go?
Our bodies are really efficient at maintaining a near constant internal temperature. The use of heat doesn’t necessarily make a big change in the local internal temperature. I found an article that said it takes a 40 degree Celsius temperature to heat tissues 2-4cm deep by only 2-5 degrees. This doesn’t sound like a huge rise in temperature, but it has been said that it only takes a 1 degree increase in temperature to cause a 10-15% increase in tissue metabolism. You can see how it doesn’t have to heat the area much in order to make good physiological change.
The best ways to use heat therapy
- Choose whatever heat source works best for you. We are all individuals and what works best for me may not work best for you. Also it will depend on what your goals are for the heat therapy. Start with deciding what you are trying to achieve by using heat and then choose the best approach described above.
- I have personally found that local heating is easier and faster to use for injury purposes. On the other hand, I always feel great after having a soak in a hot bath or spa if I am sore.
- As it is mentioned above, moist heat is generally preferred over dry heat.
- Personally, I have found that wheat bags are most effective for me. Just make sure you put a glass of water in the microwave to stop it over heating and help make it moist.
- Feel free to use creams that ‘heat’ the area. If you choose to use them, try to choose a more natural product like Kirimi (it’s the one I sell at work). It is also a NZ made product which is great.
- If you have a choice between the creams and other heat sources like wheat bags, use the wheat bag etc where possible. Use the creams if you are heading off to work or do exercise and you can’t use other, more effective sources.
- As I mentioned in my previous post, short bursts are generally more effective from a physiological perspective than leaving it on for a long time. Aim for heat application of around 20 minutes, then remove the heat and let the area cool down (approx 40min) before re-application of the heat.
So there you have the best ways to utilize heat therapy. There is no 'right' way to use heat, different methods are 'right' for different people. Try some of the advice from above and see how you feel. Of course, if the problems persist, make sure you have it assessed by a health professional, your body will thank you for it.