Ice or heat on a flared up arthritic knee? Physio says frozen peas, my mother swears by a hot water bottle, and the knee can't tell me

Overdid it on Saturday. Long walk with the dog, then two hours on my feet at a barbecue, and by the evening the right knee was hot, puffy, and doing that thing where it feels a size bigger than the left one. Sunday morning it was stiff as a board and I could hear it.

Here is the argument in my house. The physio, when I saw her, said ice, wrapped up, twenty minutes. My mother, who has had bad knees for thirty years, says ice is nonsense for arthritis and a hot water bottle is the only thing that ever helped her. My wife has now bought BOTH a gel pack for the freezer and a microwave wheat bag and put them side by side on the kitchen worktop like a dare.

So which is it? Does one of them actually do anything, or am I just picking a temperature to feel busy? Does heat make the swelling worse? Do you ice it BEFORE the walk or after? And is the swelling itself doing damage, because that's the bit that actually worries me, it feels like the knee is telling me I've broken something.

Both, at different times of day, is where I landed after ten years. Warmth first thing when it's stiff, cold in the evening when it's swollen from what I've done. Your mother and your physio are both right, they're just describing different knees on different hours of the clock.

I'll be the one who says neither did much. I've tried the peas after long rides and the wheat bag on winter mornings and I genuinely couldn't tell you either one changed the next day. What changes the next day is how far I rode. Not saying don't, they're cheap and pleasant enough, just that I stopped expecting them to do the work.

Genuinely interested in the "before or after" question though, because I've heard both from people who sounded very sure.

Short answer, Dennis: they do two different jobs, and the argument in your kitchen is really about which job the knee needs at that moment. Cold is for the hot, swollen, angry knee after you've overdone it. Heat is for the cold, stiff, creaky knee before you move it. Your mother, your physio and Pete are all describing the same thing from different ends.

Some detail from a decade of managing mine before the replacement. A cold pack, always wrapped in a tea towel and never straight on the skin, for about 15 to 20 minutes at a time, a few times over an evening, took the heat and the puffiness down after a big day and dulled the ache enough to sleep. Frozen peas are fine, they mould round the knee better than the gel packs. Heat on that same swollen knee tended to make it feel fuller, so I kept the wheat bag for mornings, when the joint had seized overnight and warming it for ten minutes before I started moving made the first stiff steps kinder. A warm shower did the same job. On the before or after question, that's the practical answer: warmth before you walk if it's stiff, cold after if it's swollen, and if it's neither, nothing at all.

Now the bit I'd want you to hear plainly. Neither of them treats anything. The guidance for knee osteoarthritis puts exercise, strength work and, where it applies, weight at the centre, and things like heat and cold sit in the "cheap, low risk, may help you feel more comfortable" category, which is exactly where the evidence leaves them. They are comfort, not treatment. What actually shrank my flares was the boring stuff you're already doing from your other threads: two shorter loops instead of one heroic walk, the next morning rule, strength work. The swelling itself, in an arthritic knee that's been overworked, is the joint lining producing extra fluid in protest, and it settles on its own over a day or two. It is not the sound of something breaking. The site's guide to knee osteoarthritis explains what is going on inside a worn joint during a flare, which I found took a lot of the fear out of it.

One caveat that matters. A knee that is hot, red and swollen when you HAVEN'T overdone it, or that comes with feeling unwell or feverish, or a flare that hasn't settled in a couple of weeks of sensible behaviour, is not a peas or wheat bag question. That goes to your GP, and the piece on knee pain and when to see a doctor lists the signs that mean same day rather than sometime. Yours, after a dog walk and two hours standing at a barbecue, sounds like a knee that has been told off, not a knee in trouble. But I haven't examined it and your physio has, so if it's still up at the end of the week, she's the one to ask.

Margaret Doyle said:

Frozen peas are fine, they mould round the knee better than the gel packs.

They do, and I'd add: label the bag. Ours went back into a shepherd's pie after a year of knee duty and nobody was told until afterwards.

More usefully, the thing that ended the ice or heat debate for me was noticing what I reached for on a normal evening, which was neither. It was the days after a big walk that I wanted the cold, and the January mornings that I wanted the heat. The knee had already sorted the argument, I just hadn't been listening.

Three weeks on. Knee settled by the Tuesday after that barbecue, so nothing broken, as promised. Wheat bag lives by the bed now for mornings, peas in the evening only when it's actually swollen, which has been twice. Both still on the worktop side by side because my wife is enjoying being right.

My mother has been told that she and the physio agree with each other. She does not accept this.