By Erin Buenger, PT, DPT

Can you get dehydrated in winter?  The answer is YES!  In fact, we are particularly susceptible to dehydration in the winter.  After just short periods in the cold, our bodies push fluids from our extremities to our central core, which increases urine output.  In addition, our bodies often fail at sending us the conscious “thirsty signal” in colder weather.  If you are performing any physical activity in winter clothing (think of the dreaded snow shoveling on the way), you may even sweat like you would in warm weather.The general current recommendation of fluid intake for adults is 2.7 L/day for women and 3.7 L/day for men.  Surprisingly, about 0.5-0.7 L (or 20% of the recommended intake) comes from foods if you are eating a well balanced diet because fruits and vegetables have high water content. Therefore, the general rule of “drinking eight 8-oz glasses of water per day” is a reasonable one, but if you are sweating, you must drink more because sweating reduces the body’s water content and alters normal bodily functions.Some beverages are better choices than others for managing and preventing dehydration.  Water is appropriate if you are performing low or moderate exercise for an hour or less.  If your goal is to exercise longer than an hour or stay in the sun or cold for a few hours, you should switch to a sports drink to replenish electrolytes additionally lost through perspiration.  Muscle cramping is one of the main signs of electrolyte deficiency, particularly sodium and potassium.  Alcoholic and caffeinated beverages tend to pull water away from the body and can contribute to dehydration without participating in any physical activity.  Fruit juice should be diluted to 50% juice and 50% water in order to keep the balance.  Other factors that can affect hydration include overall health and breastfeeding.  Our bodies also lose fluids through vomit or diarrhea if we are sick, have a bladder infection or for someone who has developed urinary tract stones.  If you experience any of these conditions, talk to your doctor about “oral rehydration solutions.” Women who are breastfeeding are encouraged to drink 3.1 L per day.Remember:

•  Drink often and before you are thirsty in all types of weather. If you are thirsty, you are already dehydrated.
•  Check the color of your urine;  aim for a light yellow color.
•  Drink 2.7 L/day for women and 3.7 L/day for men.
•  Remember that caffeinated and carbonated beverages dehydrate.
•  Monitor for signs and symptoms of heat-related disorders, depending on the temperature:
  Heat cramps:  For muscle cramps, stretch, engage in moderate activity and drink fluids.
  Heat exhaustion:  Notable for profuse sweating, cold/clammy skin, faintness, rapid pulse, hypotension.  Cease activity, rest under shade if sun is out, lie down, provide fluids.
  Heat stroke:  Notable for lack of sweat, dry/hot skin, muscle incoordination, mental confusion, disorientation.  Call 9-1-1, initiate cooling of body and immerse/douse with cool water.

While uncommon, overhydration is possible and the signs and symptoms can be similar to dehydration.  If you have health concerns or are unsure of your water intake needs talk with your doctor.

Dr. Buenger is a physical therapist with PhysioPartners.  She can be reached at (773) 665-9950.