Hydration is important in the heat of the summer, but it is just as crucial — if not more so — during the winter months.
Several factors contribute to dehydration in cold weather, including warmer indoor temperatures, cold air and less water consumption.
“You may not feel as thirsty in the winter as you do in the summer, so it’s easier for dehydration to sneak up on you,” said Janice Hermann, Oklahoma State University Extension nutrition specialist. “Cold, winter air is less humid, and a home’s heating system can pull even more moisture out of the air. Plus, the body loses air breathing out, but the moisture isn’t replaced when inhaling due to the dry air conditions.”
A person’s thirst response diminishes up to 40% in cold weather. Blood vessels constrict to prevent blood from flowing freely to the extremities. Directing that blood flow to the body’s core to protect vital organs tricks the body into thinking it’s properly hydrated. Therefore, people often drink less water, thus increasing the risk of dehydration.
Hermann said sweat on the skin evaporates almost immediately in the winter, making it more difficult for people to realize they’re losing water.
“Dehydration can be life-threatening, even causing heat exhaustion and stroke. We can tolerate losing stores of fat and carbohydrates but not water,” she said.
A 1-2% water loss can cause fatigue, weakness and loss of appetite; 3-4% loss can cause impaired physical performance, dry mouth, urine reduction and flushed skin; 5-6% results in difficulty concentrating, headache, irritability, sleepiness, impaired temperature regulation and increased respiratory rate; and a 7-10% loss can lead to dizziness, spastic muscles, loss of balance, delirium, exhaustion or heat stroke.
Hermann said some older adults are particularly susceptible to dehydration because they may limit fluid intake due to concerns about incontinence. Also, the thirst mechanism isn’t as effective as the body ages.
“Older adults often deal with muscle loss, which results in the loss of body water,” she said. “Unfortunately, many signs of dehydration are misinterpreted as being due to age.”
How much water is enough? The Dietary Reference Intake Committee set the adequate intake of liquid at 3.7 liters and 2.7 liters per day for adult males and females, respectively. This includes both water in beverages and food. About 20% of a person’s water intake comes from food, but more may be needed with increased physical activity or environmental conditions.
Hermann said any beverage can provide fluids, but some options are better than others.
“Water is the best option. Herbal teas and sugar-free hot cocoa can be soothing on a blustery winter day,” she said. “Sodas and juices count for total fluid intake, but the added sugar can pull water into the large intestine and interfere with proper water absorption.”
Caffeine does cause some fluid loss, so adults should limit caffeine intake to 400 milligrams per day. Avoid alcohol as it is a diuretic causing water loss and shouldn’t be used to meet fluid recommendations.
Tips for staying hydrated in the winter:
- Keep a water bottle handy.
- Set water-consumption goals and track daily water intake.
- Set reminders to hydrate.
- Check your hydration meter. Urine should be a pale, straw-like color when properly hydrated.
“Remember, hydration is a year-round effort that has a positive impact on your overall health,” Hermann said.
