@mike – I dont guesstimate, I work it out (you know how much insulin you get per hour, you know how long you have had it off, you do the maths!)
I can get cannulas in 30cm, 60cm or 80cm lengths for mine – might be different for other meters, but I just pick the most relevant for whatever I’m wearing, the meter is pretty much always in the same place.
I have a case on a cord that I wear at night – could be worn during the day like some people wear their mobiles round their necks.
As the vials dont last too long ( a few days to a week), in normal weather its not a problem, I dont think. There was a story recently (but I cant find the link) about a girl who took hers off to go swimming and left it in full sunlight on the side of a pool in Oz for an hour or so in 40+ degree heat – when she put it back on she didnt realise she had ‘boiled’ the insulin and she went ketotic cos the insulin wasnt working (she recovered fine). So the suggestion was to try and keep it in the shade where possible (ie not in direct sunlight). If you put it in a Frio type wallet (ie one that is supposed to keep things cooler) – you can get them/adapt them for pump type items (or mobile phones, for example) – that should do you for your lobster impression days, I’d say. And if you think you’ve let it get a bit hot, you change the cartridge to be on the safe side.