Staying Hydrated All Year Long

Humans are water-based life forms, and as such we require H₂O to function. Most North Americans benefit from an abundance of safe drinking water to keep our bodies hydrated.  We normally associate the risk of dehydration with hot weather, but a recent article from CNN Health highlights the fact that it is just as easy to become dehydrated in winter as it is in summer.

Dehydration:  Not One Season; Not One Look

Depending on the temperature and humidity of the air we find ourselves in, our perspiring may or may not provide a clue for us to drink more water. The CNN article makes the point that in a dry or high-altitude setting sweat can evaporate directly from the skin instead of coating it.  Cold winter air may be dry—cold air holds less water vapor than warm air—increasing evaporation of sweat from our skin.  In contrast, in a humid environment sweat is more likely to coat the skin because it evaporates much more slowly due to the already high water content of the air.  Yet, in both dry and humid environments water leaves our porous skin, and it is up to us to restore it.

The CNN article notes “up to 60% of a person’s body weight is water, and it only takes a 1-2% drop in that percentage to cause dehydration.” Signs of dehydration are headaches, dizziness, drowsiness, muscle cramping, nausea and vomiting, dark yellow or odorous urine, dry or sticky mouth, and dry, warm skin.  Thirst is an obvious indicator of dehydration, but thirst may become less effective an indicator as we age.

Why We Must Hydrate

Here are a few of the essential roles of water in the human body:

• Helps organs function
• Aids digestion
• Carries nutrients and oxygen throughout the body
• Controls blood pressure
• Lubricates joints
• Keeps skin moist and smooth

Tips for Staying Hydrated

• Become a water carrier:  Carry a water bottle and drink water regularly during the day; if you wait to drink until you are thirsty, you are already dehydrated. Fruit juices, uncaffeinated sports rehydration drinks and other uncaffeinated soft drinks, herbal teas and decaffeinated coffee also rehydrate.
• Eat your fruits and vegetables:  In addition to their nutritional content, fruits and veggies have high water contents. The water in the food you eat counts toward your daily water requirement (see the chart below).
• Avoid alcoholic and caffeinated beverages:   Both types of drinks can cause dehydration from increased urine output.

Water’s popularity as a beverage seems to be surging, based on the widespread availability of refillable water bottles, bottled water, and even flavored and vitamin water.  It should be easier than ever to stay hydrated, no matter what the season.

Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.