There’s always that season when one person falls sick, then another, and before you know it, most people around you — whether at the office, at home, or in school — are down too.

The common phrase people say is, “It’s because of the weather.” While I’m not a doctor, here are some light but real reasons why you may fall sick during a switch in weather, whether from hot to cold or cold to hot:

1. Weakened Immune Response
Sudden temperature changes can stress the body as it adapts. If your immune system is weak, it may fail to fight off viruses effectively.

2. Respiratory Irritation
Cold or dry air can irritate the nose, throat, and lungs, making it easier for infections like colds or the flu to take hold.

3. Virus Survival
Some viruses, like the flu, spread more easily in colder, drier air, while others thrive in warm, humid weather. This makes people more exposed during these changes.

4. Allergies and Triggers
Weather shifts can stir up pollen, dust, or mold, which irritate the airways and can make you feel sick or more vulnerable to infections.

5. Body Stress and Fatigue
Moving quickly between hot and cold environments forces the body to adjust its temperature regulation. This can cause stress and leave you feeling run-down, making it easier to get sick.