I cant find the old greenheat thread where I mentioned using the stuff with a swedish mess kit instead of the triangia so I've have to use this one instead.
As I pointed out then it works well but I was doubtful about it in cold conditions - well I have been running an experiment and the results are good.
I frozen 6 sachets in the freezer, removing one everyday for a week to see if it deteriated in the cold and am pleased to say they didnt - only problem I had was todays sachet was so iced up the the ice melted and put out the first flame! But once relighted it was ok.
Top tip I did find was that they worked better after a little rewarm in the pocket, a few seconds from freezer to garden.
Anyway - not scientific and would be interesting to see if an ambient temperature effected this test but hey it amused me!