Flasks Wherever you’re going, whether you’re off to the office, out for a walk or travelling, a flask is an essential for keeping your drink hot (or cold). Most people think of flasks and automatically think of tea or coffee, and they are brilliant for that, but you can also keep cold drinks chilled in a vacuum flask, perfect for hot days when you’re out and about. Thermos flasks are also much better for the environment than single-use, disposable cups, and their robust design means they’ll put up with a lot more in the great outdoors. So how does a coffee flask work? Its double-walled construction has a vacuum inside, which means there’s nothing for heat or cold to escape through. This means that whatever drink you put in your flask will keep hot or cold for a long time – some flasks keep hot drinks hot for as long as 12 hours, and cold drinks chilled for up to an amazing 24 hours. Not just for tea and coffee, flasks are also great for keeping food hot on the move. Think warming soup when you’re out on a wintry walk, or even a chunky casserole. Some food flasks even come with a little spoon so you can tuck in whenever hunger strikes. However, don’t put fizzy drinks in a flask, as the pressure might cause it to explode – unless you’re using Thermos’ clever carbonated drinks bottle, which means you can enjoy your favourite bubbly beverage on the move!