Staying hydrated in the cold

As temperatures dip, the most obvious signs of dehydration often disappear. An expert with Baylor College of Medicine helps understand the importance of staying hydrated in cold weather and how to identify when it’s time to drink more water. 

“In cold temperatures, the blood vessels in your extremities constrict to preserve heat and increase blood flow to the core of your body and your vital organs,” said Dr. Saundra Nguyen, assistant professor of Medicine at Baylor. “Because of these physiologic changes, your thirst response is decreased and you may urinate more often, which can lead to fluid loss and dehydration.” 

In general, it is recommended that men drink 3.7 liters (15.5 cups) of water per day and women drink 2.7 liters (about 11.5 cups) per day. Cold air and low humidity also can contribute to dehydration in the winter and there can be moisture loss with breathing cold, dry air as well. Although people who partake in physical activity experience a more visceral thirst, the signs of dehydration can be subtle. 

“Sweating is often less obvious during cold weather, because sweat evaporates more rapidly, so people can be unaware of how much fluid they’re losing, especially during exercise,” Nguyen said.  

Nguyen said that signs of dehydration include: 

• Headache  
• Dry skin and mouth, cracked lips  
• Fatigue  
• Dizziness and/or lightheadedness  
• Difficulty concentrating 
• Less frequent urination and darker urine color 

To stay hydrated, Nguyen offers these tips: 

• Jumpstart your day with a glass of water 
• Keep a reusable water bottle with you and monitor your fluid intake throughout the day 
• Hydrate by eating water-rich foods such as cucumber, watermelon, berries, melons and tomatoes, as approximately one-fifth of your fluid intake comes from food 
• If you are wearing multiple layers of clothing to keep warm, hydrate often 
• Humidifiers, if you have one, can help retain moisture in the air during dry days

Learn more about Baylor Medicine Primary Care.