Most people’s instinct is to reach for ice when something is sore. I get it. It's already in the freezer and you feel it doing something within about a minute. Find out below why it's usually the wrong first move.
For ordinary mechanical low back pain, heat is the better default. Superficial heat application has been shown to be one of the most recommended non-pharmacological treatments [1], and a JAMA review published in July lists heat as a first-line treatment for new non-specific back pain, while ice doesn't appear at all [2]. Ice isn't useless. It just may be less effective than you think.
What heat and ice actually do
Both get sold like they're doing something dramatic under the surface. They aren't.
Heat widens the blood vessels near the skin, warms the tissue underneath, and makes muscle a bit more pliable. In simpler terms, it increases blood flow to the area of heat application. It also floods the area with a strong, harmless sensation, and your nervous system has limited attention to go around. Exactly how that translates into less pain is still argued over. Ice does roughly the reverse. It narrows the blood vessels, slows how fast nerves fire, and eventually numbs the area.
So what are you actually treating when you apply heat or ice to an area? Well, your discs are underneath centimetres of skin, fat, muscle, and ligaments. It’s unlikely that your topical application of heat or ice actually reaches the spine. But that doesn’t mean it’s pointless. The top layers of muscle are warmed or cooled, and the sensations themselves may lead to some psychological relief, which isn’t nothing.
The case for heat
A network meta-analysis (a method for ranking many treatments against each other even when no single study compared them head to head) pooled 46 trials and 8,765 people whose back pain was under 12 weeks old [3]. For immediate pain relief, applying a heat wrap finished second, tied with exercise and ahead of opioids, manual therapy and anti-inflammatories.
I used that same paper back in July writing about back spasms, where it was part of why I told you to get a heat wrap on in the first day or two. This is the longer answer.
A study applied heat to the calves for 20 minutes and then measured the muscle temperature 1.5 cm into the muscle [4]. Muscle temp only rose 1.7°C on average. That’s well below the amount required to introduce real tissue laxity, but it may be calming to the nervous system.
There’s an important caveat to state here. Nearly every heat wrap trial in both of those reviews came from the same place: a small cluster of studies funded by Procter & Gamble, the company that made ThermaCare heat wraps, with P&G employees listed as co-authors. That doesn't make the results wrong. These were randomised trials and industry-funded research can be well run. But when a manufacturer funds most of the evidence for its own product, the effect tends to shrink once independent groups try to replicate it.
Ice has almost no evidence behind it
The Cochrane review on this (Cochrane reviews pool every trial on a topic and grade how trustworthy each one is) found nine trials covering 1,117 people [5]. Cold got three studies, all rated poor quality, and the reviewers wrote that no conclusions can be drawn about using cold for low back pain. Read that carefully. The trials haven't caught ice failing. They mostly haven't been run.
To be fair to ice, the heat case has a boundary too. It's strongest in the first twelve weeks. For back pain that's been hanging around longer, a review of 83 trials found there wasn't enough data to say anything firm about superficial heat or cold in either direction [6].
On another note, I’ve always had a bone to pick with ice baths. Athletes and influencers often tout that they use them for recovery and cite them as integral to their routine. This claim doesn’t make sense, at all. As far as we can tell, applying ice or cold temperatures to a tissue reduces the processes that promote adaptation. A muscle that’s torn up from a workout requires greater blood flow to clear metabolites, recruit immune cells, clear damaged cells, and initiate muscle protein synthesis. Subjecting the body to frigid cold temperatures does the opposite of that. Perhaps people like ice baths because they reduce soreness, but for me personally, if I’m going to bust my ass during a workout, I want to get the full reward from it.
When ice earns its place
Real trauma and large amounts of swelling. If you came off a bike or took a hit and there's swelling and bruising, ice has a job heat can't do. Cold slows the local response down. Heat would push it along.
What you can try
- Try heating your back for 15 to 20 minutes, two or three times a day. This can feel good during a flare-up or on days when you ask a lot of your back. Hot water bottle, microwaveable bag, or a stick-on heat wrap. Warm, not scalding.
- Put a layer between it and your skin. A t-shirt is plenty. And don't fall asleep on a heat pad, especially a plug-in one. That's how people end up with burns.
So if you've been icing out of habit, give heat a try this week.
As always, have a great weekend.
Best,
Mitch
Want to know which back pain pattern matches you? Take my free 2-minute quiz and find out.
References
[1] Qaseem et al., 2017. Noninvasive Treatments for Acute, Subacute, and Chronic Low Back Pain: A Clinical Practice Guideline From the American College of Physicians. Annals of Internal Medicine, 166(7), 514-530. doi:10.7326/M16-2367
[2] Cashin et al., 2026. Low Back Pain: A Review. JAMA, 336(2), 144-158. doi:10.1001/jama.2026.9631
[3] Gianola et al., 2021. Effectiveness of treatments for acute and subacute mechanical non-specific low back pain: a systematic review with network meta-analysis. British Journal of Sports Medicine, 56(1), 41-50. doi:10.1136/bjsports-2020-103596
[4] Ostrowski et al., 2019. Comparison of Muscle Temperature Increases Produced by Moist Hot Pack and ThermoStim Probe. Journal of Sport Rehabilitation, 28(5), 459-463. doi:10.1123/jsr.2017-0294
[5] French et al., 2006. Superficial heat or cold for low back pain. Cochrane Database of Systematic Reviews, 2006(1), CD004750. doi:10.1002/14651858.CD004750.pub2
[6] van Middelkoop et al., 2011. A systematic review on the effectiveness of physical and rehabilitation interventions for chronic non-specific low back pain. European Spine Journal, 20(1), 19-39. doi:10.1007/s00586-010-1518-3
Disclaimer: this content is educational only and does not constitute medical advice. See a practitioner if you suspect serious spinal trauma from a fall or accident, or if you experience any of the following red flag symptoms: loss of bowel or bladder control, numbness in the groin or saddle area, rapidly worsening leg weakness, back pain with fever or feeling generally unwell, or unexplained weight loss with back pain.