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Heat therapy – Is it helpful for my injury?

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Read time: 4 minutes

Heat Therapy (thermotherapy)​

Why do we use it? You perhaps are wondering…

Now – I know you’re confused… you thought it was ice/cold for injuries right? To bring the swelling down obvs? You’re not the only one that’s confused, trust me! Where has heat ever popped up (?) I can almost feel your apprehension but don’t worry I’m going to explain the basics. Except for menstrual cramp relief, before I went to University I had never heard of people using heat for an injury or pain relief!

So, what does it do? and how do we use it? – stick with me, we will unpack this hot topic together!


I would also encourage you to open up our previous blog on Ice in a new tab for reading after this, if you haven’t seen it yet! Click here!

Now, if you’re anything like me, you’ll have never considered the use of heat for anything except maybe a hot bath after a sports match… Heat was not even on my radar as a treatment tool until well into my Undergraduate degree, so it’s something that was fascinating to discover and use in my practice as a tool to help people out of pain, or at least to take the edge off.

Heat therapy, or thermotherapy is literally the exact opposite as ice/cold therapy (cryotherapy) – but it has many more uses than most of us twig onto.

One of the main benefits of heat therapy that has been noticed is it’s use of symptom relief for muscle soreness. Muscles can cause us all sorts of grief for all sorts of different reasons and heat has been found to soothe the symptoms we are experiencing.

This cheap and easy therapeutic modality has been brushed over by science and therefore there is not a terribly long list of studies proving its effectiveness. 

Having said that, it’s uses should not be ignored: it still remains one of the staple tools in a physio’s toolkit, predominantly because it’s easy, cheap and doesn’t require a medical professional to apply – and has been suggested it takes the edge off all sorts of injuries from lower back pain to osteoarthritic pain.

What does a hot water bottle or heat pad actually achieve then?

Heat’s main benefit is it appears to have an analgesic (pain relieving) effect on muscle soreness. Muscle pain can be caused by all sorts! From a cramp to an overextension/overstretch all are common causes of pain we feel, but they can regularly be mistaken for other problems.

What SHOULD you be using the hot water bottle for then?

The top uses for heat are:

  • comfort,
  • relaxation,
  • coziness and
  • taking the ache out of various types of pains.

These pains are usually those crampy, stiff pains, you know the ones you get after the first 5 a side game back after a summer off, or perhaps that first steady 3k you did after Christmas – the one you can REALLY feel (I’ve been there so many times)

It can also be soothing for those stiff/achy pains, for example those creaky knees, or stuck hips, those kind of areas that we generally associate with osteoarthritis or dodgy joints. (nice have some prescriptive recommendations on this front, see here) It can also help with the pain in specific areas like muscle ‘knots’ or spasms such as postural stress (been sat at your desk for a bit too long and really feel it in your shoulders? Try a heat pack!).

It can also be hugely beneficial to that all over ache, e.g. rheumatoid arthritic pain or maybe chronic pain or fibromyalgia symptoms.
These are just a few of the ‘types’ of pain that heat can be a huge relief for, but there are plenty others I haven’t listed!

Now, there are a few conditions heat is NOT great for…

For some conditions heat can be detrimental, so just keep this in mind before you reach for the hot water bottle!

A general rule of thumb for when not to use heat:

  • New/fresh injuries, i.e. just rolled your ankle this morning? Grab an ice pack, NOT a hot bath. Using heat on a fresh injury or any acute inflammation is a BAD idea!
  • Damaged tissues (e.g. a pulled hamstring or strain) When a tissue gets damaged it gets inflamed for a few days, the inflammation starts the healing process, and it’s likely the area will be tender to the touch, perhaps will feel hot already, maybe bruised, swollen, all of these signs are indicative of a new injury and should not be heated further (see this article on cold therapy). So swap that hot bath for a bag of frozen peas! 
  • Another no no for hot stuff is infections, if your arm is throbbing due to cellulitis or similar, steer clear of the heat pack, infections trigger the immune system to start that healing response and fight the infection. Heating isn’t going too help with this one! 

Now, if you haven’t noticed any of these symptoms, you’re probably in the clear and it should be fine for you to try a heat pack/hot bath!

How does heating an area actually make a difference?
Well, as we said before, there isn’t so much evidence to support either way, but one of the first and foremost things we have found is that heat is reassuring and as stated by Paul Ingraham in his blog post ‘reassuring is analgesic’.

If your comfy, you’re generally not focusing so much on pain, and often comfort = warm – if you catch my drift… 

Heat therapy has also been suggested to have a biochemical effect on the tissues (think back to GCSE chemistry, or was it biology? heat = cells bounce faster, cold = cells bounce slower, in my memory they used the yeast example!).

Heat penetrates a couple of centimetres into the tissue… speeding things up, which has been suggested to have a therapeutic effect. 

If we think logically, if cells are moving faster than usual, there is a potential for a beneficial therapeutic change.


How far does the heat penetrate?

Good question… Well, according to this study: Skeletal muscle adaptations to heat therapy only a couple of centimetres or so, but they also explain that it depends on the temperature, the time the tissue is exposed and various other factors. If you want specifics, this (Hot-Pack and 1-MHz Ultrasound Treatments Have an Additive Effect on Muscle Temperature Increase) is a good paper, it explains tissue heating in depth!


So, after all of that, what have we actually learned?

  1. That heat therapy (therm-therapy) is not nonsense and can be very effective both psychologically and (we think!) physiologically when used correctly.
  2. What it can be used for, and what you shouldn’t be using heat for.
  3. And finally, that heat therapy falls under the same category as ice, in that its cheap, easily accessible, and can be highly effective when used correctly/for the appropriate ailments!

The overarching advice, as with all of our posts, we have just discussed some tips and tricks that might help get you out of pain/set you in the right direction towards getting better. If there is anything you’re seriously concerned about or struggling with please don’t hesitate to get in touch via email, phone or pigeon mail.

If you are in pain, or have an injury book yourself in below to start your recovery today!

References (in addition to in-article)

I would also encourage you to open up our previous blog on Ice – if you haven’t seen it yet! Click here!

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