A twisted ankle, lower back pain at the end of a long day, a knee that complains on the stairs, or a headache that will not go away. Before reaching for medication, many people start with a simple solution: applying cold or heat to the sore area. These are called cryotherapy (cold) and thermotherapy (heat) and, when used properly, they are among the most accessible, affordable and natural ways to ease discomfort at home.
In this guide we explain how each one works, when to choose cold or heat, what the scientific studies say and how to use GelPro gel packs safely.
How does cold (cryotherapy) work?
When we apply cold, the blood vessels in the treated area constrict and local circulation decreases. This helps to reduce swelling and to "calm" the nerve endings, which lowers the perception of pain. That is why cold is usually recommended in the first hours and days after a knock, a sprain or an injury with swelling, and also for headaches.
How does heat (thermotherapy) work?
Heat does the opposite: it widens the blood vessels, increases circulation and relaxes the muscles. That is why it is suitable for stiffness, muscle tightness and muscle aches without swelling, and for preparing the body before stretching or gentle exercise.
When to use cold and when to use heat
| Situation | Usually recommended |
|---|---|
| Recent knock, sprain or injury with swelling (first 2 to 3 days) | Cold |
| Headache or migraine | Cold |
| Sore joint that feels warm (for example, the knee) | Cold |
| Muscle stiffness, tightness and spasms | Heat |
| Lower back pain from muscle tension | Heat (or cold, depending on which feels better) |
| Chronic joint stiffness | Heat |
The UK's National Health Service (NHS) advises that, for recent injuries, ice should be applied during the first 2 to 3 days and heat should be avoided during that period so that swelling does not increase. For back pain, it suggests using cold for pain and swelling and heat for joint stiffness and muscle spasms.
What the scientific studies say
The evidence on cold and heat is encouraging, but it should be read honestly: the effects are generally modest and short-term, and many studies are small. Even so, the risk is low when the application is done correctly. Some examples:
- Low back pain: a Cochrane review (French et al., Spine, 2006) concluded that there is moderate evidence that heat wraps reduce pain and disability in the short term in acute and sub-acute low back pain, and that combining them with exercise improves results further. For cold, the evidence was considered insufficient. View study.
- Muscle soreness after exertion: a meta-analysis of 32 randomised controlled trials with 1,098 people (Wang et al., Physical Therapy in Sport, 2021) showed that both heat and cold reduce pain in the first 24 hours, with no significant difference between them. View summary.
- Knee osteoarthritis: a systematic review and meta-analysis of 5 trials and 201 participants (Dias et al., Pain Practice, 2025) found a moderate short-term reduction in pain with cryotherapy, especially when combined with exercise, although the evidence on function remains limited. View study.
- Migraine: in a study where each participant acted as their own control (Cura and Acaroglu, Clinical and Experimental Health Sciences, 2020), applying a cold band to the forehead reduced pain intensity at 30 and 60 minutes and improved quality of life in people with migraine. View study.
Why it is often the first choice: natural, simple and affordable
Cold and heat applied locally are often one of the most natural and accessible treatments within our reach. They are among the self-care tips the NHS gives for sprains, strains and back pain, they involve no drugs and they can be repeated whenever needed. A gel pack is reusable: you keep it in the freezer or warm it according to the manufacturer's instructions and it is ready for next time. For the GelPro Headband, for example, the manufacturer states an estimated lifespan of 5 years under normal use.
It does not replace medical diagnosis or treatment, but it is an excellent first step to have at home, especially for people who play sport, sit for many hours at work, are in rehabilitation or suffer from frequent joint pain.
Practical examples: which GelPro pack to use in each situation
Headache and migraine: GelPro Headband
When your head feels heavy or a migraine begins, cold on the forehead and temples can bring a pleasant sense of relief. The GelPro Cold Headband contains gel inside an ultra-elastic fabric that is easy to place on the head: keep it in the freezer and use it for up to 20 minutes.
Sprains and ankle pain: GelPro Ankle Pack
After a twist or a demanding workout, cold helps control swelling in the first hours. The GelPro Thermotherapy Ankle Pack wraps around the joint and is fixed with a strap, leaving the ankle covered and comfortable.
Knee, thigh and elbow: GelPro tubular packs
The elastic tubular format slides easily over the leg or arm and keeps the pack in place without needing to hold it. It is available for thigh and knee and for elbow and knee, useful for joint discomfort, recovery after exertion and rehabilitation.
Lower back pain: GelPro Lumbar Pack
For the lower back, where heat often eases stiffness and cold soothes pain and swelling, the GelPro Hot and Cold Lumbar Pack follows the curve of the back and can be used in either mode, according to the manufacturer's instructions.
You can see all the products in our Thermotherapy collection.
How to apply cold and heat safely
- Time: apply each session for about 15 to 20 minutes and take a break before repeating. The NHS advises up to 20 minutes at a time, every 2 to 3 hours, for recent injuries.
- Protect your skin: do not apply extreme cold or heat directly to the skin. Wrap the pack in a thin cloth or towel, as the NHS recommends.
- Check your skin: remove the pack if you feel burning, persistent numbness, or if the skin becomes very red or whitish.
- Heat after cold: for recent injuries with swelling, avoid heat during the first 2 to 3 days.
- Do not fall asleep with the pack on: the manufacturer of the GelPro Headband advises against using it while sleeping.
- Special care: seek medical advice before use if you have diabetes, circulation problems, heart disease or are pregnant, and do not apply it to broken or damaged skin. Do not use it on small children or on people who cannot remove the pack themselves.
When to talk to a healthcare professional
Seek medical advice if the pain is severe, getting worse, lasting more than a few days, or accompanied by fever, numbness, weakness, redness or marked swelling, or if it appears after a fall or an injury. Thermotherapy and cryotherapy are complementary care and do not replace medical diagnosis or treatment.
Frequently asked questions
Cold or heat for lower back pain?
It depends on how it feels and on the stage. Heat usually eases stiffness and muscle spasms; cold helps when there is acute pain and swelling. The evidence does not show a clear difference between the two, so you can choose whichever brings you more relief.
How long should I apply the pack?
In general, about 15 to 20 minutes per session, with breaks between applications, and always with a cloth between the pack and your skin.
Can the same pack be used for cold and heat?
GelPro hot and cold packs can be used in either mode, following the manufacturer's instructions. The GelPro Headband is designed for cold use.
Do cold and heat replace medication?
They can help ease discomfort without drugs and are often a good first measure at home, but they do not replace medical assessment and treatment when pain is strong or persistent.
References
- French SD, Cameron M, Walker BF, Reggars JW, Esterman AJ. A Cochrane review of superficial heat or cold for low back pain. Spine. 2006;31(9):998-1006. Link
- Wang Y, Li S, Zhang Y, et al. Heat and cold therapy reduce pain in patients with delayed onset muscle soreness: a systematic review and meta-analysis of 32 randomized controlled trials. Phys Ther Sport. 2021;48:177-187. Link
- Dias RF, de Lima Silva S, de Mello SP, et al. Cryotherapy in knee osteoarthritis: a systematic review with meta-analysis. Pain Pract. 2025. doi:10.1111/papr.70055. Link
- Cura SU, Acaroglu R. Effects of cold band application treatment on pain and quality of life in migraineurs: a self-controlled study. Clin Exp Health Sci. 2020;10(2):166-171. Link
- NHS. Sprains and strains. nhs.uk
- NHS. Back pain. nhs.uk
This article is for information only and does not replace the advice of a healthcare professional.