Having a break with something hot to drink or to eat is a wonderful part of the outdoor life. But a vacuum bottle filled with hot water can also help out when the unforeseen happens: if you are in a cold climate, hot drinks can prevent you from getting cold or even avoid hyperthermia. You can also use a vacuum bottle with hot water to heat your sleeping bag.
A good vacuum flask should last for a long time. Learn how to get the most out of your flask here.