Cold Waves And Health: Hidden Risks To Immunity, Hydration And Overall Well-Being

Cold waves are often viewed as a seasonal inconvenience, but their impact on health goes far beyond discomfort. During periods of extreme cold, the body undergoes several physiological changes that can weaken immunity, increase susceptibility to infections, and affect overall recovery from illness. Understanding these risks and addressing common misconceptions is key to staying healthy during severe winter conditions.

Dr Abhijit Ahuja, Pulmonologist at Saifee Hospital, Mumbai, shares what you need to know.

Why Immunity Weakens During Cold Waves

Cold weather creates conditions in which infections spread more easily. Low temperatures cause blood vessels in the nose and upper respiratory tract to constrict, reducing blood flow and limiting the rapid

movement of immune cells to these vulnerable entry points. As a result, the body’s first line of defence against viruses and bacteria becomes less effective.

Cold air is also typically dry, allowing respiratory viruses to survive longer and spread more efficiently. Compounding this issue are shorter daylight hours during winter, which can reduce vitamin D levels. Vitamin D plays an important role in immune regulation, and low levels have been linked to an increased risk of infections.

To strengthen immune defences during cold waves, it is important to follow basic health practices: consume a balanced diet rich in fruits, vegetables, and adequate protein; ensure sufficient vitamin D through safe sunlight exposure or supplementation if advised by a doctor; prioritise 7–9 hours of quality sleep; and remain physically active, even indoors. Good hand hygiene, stress management, staying warm, and avoiding sudden temperature changes further support immune resilience.

Dehydration: A Hidden Winter Health Risk

Dehydration is commonly associated with hot weather, but it is often overlooked during winter. Cold temperatures suppress the sensation of thirst, leading many people to drink less water even though the body continues to lose fluids. Moisture is lost through breathing, sweating under heavy clothing, and increased urination triggered by cold-induced diuresis. Heated indoor environments can further worsen fluid loss.

Inadequate hydration can thicken respiratory secretions, making it harder for the body to clear infections. It can also impair circulation, digestion, kidney function, and concentration. For individuals recovering from illness, dehydration may slow healing, increase fatigue, and raise the risk of complications such as urinary tract infections or electrolyte imbalances. Regular intake of water, warm fluids such as soups, and herbal teas along with conscious monitoring of fluid consumption is essential during cold waves.

Cold-Weather Myths That Increase Vulnerability

Several common myths can create a false sense of security during severe cold conditions. One such belief is that layering clothes alone is sufficient for protection. While layering is important, it must be combined with dry, insulated, and wind-resistant clothing. Damp garments, inadequate footwear, and exposed extremities can still result in significant heat loss and increase the risk of hypothermia.

Another misconception is that staying indoors eliminates health risks. Poor indoor ventilation can increase exposure to viruses, air pollutants, and allergens. Reduced physical activity and limited sunlight exposure may also negatively affect immunity and mental well-being. Additionally, the belief that cold weather “kills germs” is misleading, many respiratory viruses actually thrive in cold, dry conditions.

Staying Safe During Cold Waves

Protecting health during cold waves requires a comprehensive approach that includes appropriate clothing, adequate hydration, balanced nutrition, proper ventilation, regular movement, and timely medical care when needed. Most importantly, individuals should seek medical advice for personalised guidance and avoid relying solely on home remedies, particularly when symptoms persist or worsen.

Cold waves may be seasonal, but their health impact can be serious. Awareness, prevention, and early medical intervention remain the most effective tools for staying well through the winter months.