Does anyone know whether the insulated mugs / flasks as pictured actually work okay, don't leak, etc? I imagine someone here must have tried one.

They're pretty good Stu, I've had the same one for a few years now. Will keep drinks warm for a few hours but once its been opened, it's probably best to drink all of it otherwise it goes cold quickly.

Best to store it upright in transit though as some of the models from a couple of years ago didn't have the best seals

I've had a couple and they've been brilliant. Never had a seal fail, Often stick a brew into one while heating water for dinner and leave it sealed to have just before bed. Often gaps of 5-6hrs with no worries, and have had a 'forgotten' brew still warm enough to drink happily first thing in the morning.

These mugs have an air gap to help with insulation and on cheap ones they are not sealed very well if at all. These should not be immersed in water (washing up) as the air gap then fills with water and it loses it's heat holding properties. My stepdaughter has been through a few but she is a teenager and won't listen .

Pyro wrote:I've had a couple and they've been brilliant. Never had a seal fail, Often stick a brew into one while heating water for dinner and leave it sealed to have just before bed. Often gaps of 5-6hrs with no worries, and have had a 'forgotten' brew still warm enough to drink happily first thing in the morning.

I have a Life venture one I use for me tea on the morning commute. Great for anything up to 2hr but starts to cool a lot after that. Must be doing something wrong

This flask from lakeland on the other hand is brilliant, I have to leave it for 3hr before even start to think about drinking from it!
http://www.lakeland.co.uk/16681/Lakelan ... Pour-Flask

Found a cheap versions from one of the supermarkets, Morisons I think, that looks and works exactly the same but cost £3.99

Thanks folks, I've taken a punt on a Lifeventure one as Wiggle had them bundled with a cosy for £15. If it keeps a brew hot for a couple of hours I'll be happy enough.