Cold Wave and Fever in Delhi: What’s Happening, Why It Matters & How to Stay Safe

Delhi and the National Capital Region (NCR) are currently experiencing intense winter conditions, a mix of temperatures plummeting below normal, persistent fog, and worsening air quality. These weather patterns aren’t just an inconvenience; they are directly linked to a noticeable surge in respiratory illnesses and fevers among residents.

Delhi’s Winter: Cold Wave, Fog & Pollution

In December 2025, Delhi recorded its first cold wave of the season, with the maximum temperature dipping as low as 16.9°C, significantly below the seasonal average. The India Meteorological Department (IMD) stated that two major monitoring stations — Safdarjung and Palam, reported conditions qualifying as a cold wave. This change brought colder days, chillier nights, and a marked drop in overall temperature.

Alongside the cold, dense fog has blanketed the city repeatedly, prompting orange and red alerts from the IMD. The fog has severely disrupted transport, reducing visibility and leading to delayed flights and trains. 

At the same time, pollution levels measured by the Air Quality Index (AQI) remain dangerously high. Recent readings have reported AQI figures in the ‘very poor’ to ‘severe’ range, making the air hazardous for sensitive groups such as the elderly, children, and those with respiratory conditions. 

Why Cold Weather Triggers Illness

Cold waves and temperature swings affect the body’s immune response. Sudden drops in temperature make it harder for the respiratory system to fend off viruses, while dense fog and stagnant air trap pollutants and pathogens close to the ground. The combination of cold stress, trapped pollution, and higher humidity makes the respiratory tract more susceptible to infections.

Doctors across Delhi hospitals are observing this pattern. Many patients are reporting symptoms such as fever, cough, sore throat, body aches, headache, and general weakness. While most of these cases are mild, some patients take longer than usual to recover, especially those with weaker immunity or underlying conditions.

Rise in Respiratory Viral Infections

Weather changes have coincided with an increase in respiratory viral infections, including several cases of H3N2 influenza.

Unlike common colds, H3N2 can cause more severe symptoms and has shown a noticeable spike with hospitals reporting a clear uptick in positive cases compared to earlier months.

Meanwhile, ongoing weather swings, warm afternoons followed by chilly nights, also weaken immunity and make people more prone to coughs, sneezes, sinusitis, bronchitis, and other viral illnesses.

Common Symptoms to Watch For

During this cold and viral season, you may notice:

• Fever and chills

• Persistent cough or sore throat

• Body aches and headaches

• Fatigue or weakness

• Runny or congested nose

These symptoms can be caused by influenza viruses, common cold viruses, or seasonal viral infections aggravated by cold air and pollution.

Who Is Most At Risk?

While anyone can get ill, certain groups should be extra cautious:

• Children and infants

• Elderly individuals

• People with asthma or COPD

• Those with weakened immune systems

• Individuals with chronic illnesses

These groups are more likely to develop complications or prolonged illness.

Precautions : How to Stay Safe

Here are practical steps to protect yourself and your family during the cold, foggy, and high-pollution season:

1. Dress in Layers: Warm, layered clothing helps regulate body temperature and reduces the risk of chills.

2. Avoid Outdoor Exposure During Peak Fog: Dense fog traps pollutants; stay indoors especially in early morning and late evening.

3. Wear Masks Outdoors: An N95 or surgical mask can filter out pollution particles and reduce viral transmission.

4. Hydrate & Eat Nutritious Foods: Warm fluids, soups, and vitamin-rich meals (especially including Vitamin C and zinc) can strengthen immunity.

5. Keep Indoor Air Clean: Use air purifiers or keep windows closed during high-pollution days to reduce inhalation of harmful particles.

6. Seek Early Care: If symptoms worsen or last beyond a few days, consult a healthcare professional rather than self-medicating.

When to Seek Medical Attention

If you or someone in your home experiences:

• High or persistent fever

• Difficulty breathing or chest pain

• Dizziness or confusion

• Severe cough with phlegm

• Symptoms lasting more than five days

…seek medical attention immediately, as these could indicate complications or more serious infections.

Final Thoughts

Delhi’s cold waves and dense fog are more than just weather patterns, they are catalysts for a rise in respiratory illnesses and fevers, exacerbated by poor air quality and immunity-challenging conditions.

Being informed, adopting preventive measures, and monitoring health closely can help you and your loved ones navigate this season safely.

Stay warm, stay aware, and don’t ignore the early signs of illness.

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The Author :

Dr. Sunil Khattri 

sunilkhattri@gmail.com

+91 9811618704

Dr Sunil Khattri MBBS, MS(General Surgery), LLB, is a Medical doctor and is a practicing Advocate in the Supreme Court of India and National Consumer Disputes Redressal Commission, New Delhi.