We need to drink more water in summer than winter? Right?
Wrong. In fact, the danger of dehydration in winter can be as great, if not greater, than in summer. During those balmy summer months, we tend to ensure we have our water bottles to hand and pay frequent visits to the water dispenser. In winter it’s easy to forget just how dehydrated we might become.
Water Dispenser and Hydration Association General Manager, Phillipa Atkinson-Clow says: “It’s not just during exercise, such as winter sports, that maintaining fluid levels is an issue. Wearing heavy clothes and sitting in over-heated rooms, in a heated train, bus or car, can imperceptibly cause dehydration. The temptation is to drink more warm liquids and that often means caffeinated beverages like coffee or tea that can have a diuretic effect.”
Studies on survival in Arctic temperatures have shown that participants didn’t report thirst until they came indoors and warmed up. Whilst they were in fact dehydrated from the cold, their bodies didn’t tell them as cold stress breaks the thirst mechanism. Most of us aren’t in the Arctic, but when you are in cold temperatures, it is important to remember that even if you don’t feel thirsty you still need to ensure that you keep up your fluid levels.
“Any fluid hydrates you,” says Phillipa, “but if you are trying to cut calories and reduce caffeine, the best choice is water. Not all water is equal. Water dispensers deliver great-tasting, convenient water and if it is a WHA-safe cooler – that is, a machine supplied by an accredited member of WHA, you can be assured the water is safe and hygienic. Of course, using a dispenser is also more sustainable than buying single use plastic bottles of water.”
In cold weather, we lose fluids through respiratory water loss. When you can see your own breath, that is lost water vapour and the more intense the exercise, the more vapour you lose when you breathe. Sweat evaporates more quickly in cold air. We often don’t even notice that we are sweating in cold, dry weather, because it tends to evaporate quickly, and this is another factor that can contribute to a reduced thirst response. Wearing extra clothing helps conserve heat but the added weight is estimated to make the body work between 10% and 40% harder which causes water loss through perspiration.