What to do for a minor burn: cool running water for 20 minutes, not ice or butter

The evidence-based response to a minor burn is plain running water. Cool the burn under a tap, or soak it in a cool-water bath, and keep it there — the MedlinePlus first-aid guidance says to hold a minor burn under cool water, not ice water, for at least 5 to 30 minutes [s1]. What you should not reach for is just as important: no oil, butter, ice, cream, or household remedy [s1]. The folk cures do nothing useful, and ice can deepen the injury it is meant to soothe.

The one number worth remembering

Burn services have converged on a specific target. The current recommendation for optimum first aid after a burn is water cooling for 20 minutes within three hours of the injury [s2]. That window is generous — cooling still helps well after the moment of the burn — but the duration matters, and most people fall short of it. In a study drawn from the Burn Registry of Australia and New Zealand, cooling was provided before admission to a burn centre for 68% of patients, but for at least the full twenty minutes in only 46% [s2].

That study is the strongest human evidence that the water actually changes outcomes rather than just easing the sting. Analysing patients treated between 2009 and 2012 and adjusting for confounding, it found that cooling first aid was associated with a lower chance of needing a skin graft — the probability fell by 0.070 from 0.537, a 13% reduction [s2]. Admission to intensive care fell further, by 0.084 from 0.175, a 48% reduction, and average hospital stay dropped by 2.27 days from 12.9, an 18% reduction [s2]. All of those outcomes except death showed a dose-response relationship with how long the burn was cooled — more minutes under water, better results [s2].

This is observational evidence, not a randomised trial, so it cannot prove cause on its own; the authors controlled for the obvious confounders but people who receive good first aid may differ from those who do not. Still, the direction and the dose-response are consistent with decades of animal and laboratory work, and they line up with a simple, free, low-risk action.

Why not ice

The instinct to grab ice is understandable and wrong. The MedlinePlus guidance is explicit that ice does not belong on a burn, and that a severe burn should never be put in cold water because it can cause shock [s1]. The registry study makes the same point from the other direction: it notes that evidence exists to suggest overcooling can be detrimental [s2]. Cool is the target, not cold. Running tap water sits in the right range; ice and iced water overshoot it.

The other discarded remedies are simpler to dismiss. Butter, oil, toothpaste and the rest trap heat and introduce contamination, and the guidance lists them among the things not to apply [s1]. Blisters should be left alone — the advice is not to disturb blistered or dead skin, because intact skin is a barrier against infection [s1].

After the water

Once the burn is cooled, the useful steps are modest. Cover it with a dry, sterile dressing or clean cloth; over-the-counter ibuprofen or acetaminophen can ease pain and swelling, though aspirin should not be given to children under 19; and once the skin has cooled, a moisturising lotion with aloe can help [s1]. Check that tetanus vaccination is up to date, since burns break the skin [s1]. Most minor burns heal without further treatment [s1].

When a burn is not minor

The whole approach above is for a genuinely minor burn. MedlinePlus says to call emergency services for a burn that is very large — about the size of the person's palm or larger — that is severe or full-thickness, that was caused by chemicals or electricity, or where the person shows signs of shock or breathed in smoke [s1]. For a minor burn, it advises contacting a clinician if pain persists past 48 hours, and seeking care promptly for signs of infection such as drainage, fever, increased pain or spreading redness [s1]. Which category a given burn falls into, and when it crosses from nuisance to emergency, is a judgement this article does not make — but the first response, for almost any burn, is the same undramatic thing: get it under cool running water, and keep it there.