AsapSCIENCE - Does Being Cold Make You Sick?

Short Summary

Main recommendation: Being cold does not directly cause a cold, since colds are caused by viruses, but cold weather and cold exposure can make you more susceptible by weakening immune response and changing how the virus behaves. The video suggests that going outside bundled up, rather than avoiding the cold entirely, is a practical compromise for getting through winter healthily.

Key Points

• Colds and flu are caused by viruses, so you will not catch one from cold temperatures alone if no viruses are around you.
• Winter increases exposure because people stay indoors more, placing them in closer contact with others and giving pathogens more chances to spread.
• Dry winter air reduces humidity, which helps some viruses spread more readily and dries out nasal mucus that normally acts as a protective barrier.
• Recent evidence suggests cold can impair immunity: in one study, people who had their feet placed in ice water were more likely to develop cold symptoms in the following days.
• The cold virus itself appears to be more durable in winter, since its outer envelope hardens into a shield that helps it spread more easily.

Details Worth Noting

• Concrete instructions: Go outside more often and dress warmly (bundled up) during winter, as this balance is suggested as a likely way to get through the season unscathed. The video gives no further specific steps, amounts, or timing.
• The proposed mechanism is that cold causes blood vessel constriction, slowing white blood cells from reaching the virus, and that temperature-induced stress raises cortisol, which suppresses the immune system.
• Studies on mice and human airway cells found the immune response to the common cold virus is temperature dependent, with warm-infected cells more likely to undergo programmed cell death to limit infection.
• Between 5 and 20% of Americans catch a cold or flu each year around late fall and winter, according to the video.
• Vitamin D, which the body gets from sunlight, may be lower in winter due to shorter days and more time indoors, which can adversely affect the immune system.

Bottom Line

Cold air alone does not give you a virus, but winter conditions and cold-related immune effects can make infection more likely, so warm, sensible outdoor time is a reasonable middle ground.