What is a key factor contributing to the prevalence of upper respiratory infections in colder months?

• A. Higher UV exposure
• B. Increased humidity levels
• C. Indoor crowding
• D. Lower temperatures

Answer: (C)

When people spend more time indoors in the colder months, they are in closer contact with others, share ventilation, and touch common surfaces more often. This increases the opportunities for respiratory viruses to spread through droplets, aerosols, and contaminated objects, raising transmission and making upper respiratory infections more common. While temperature and humidity can influence virus survival and our defenses, the most impactful factor in this context is the higher rate of person-to-person contact due to indoor crowding.