Does Getting Cold Actually Make You Sick?

The scene is familiar. Headed out the door with damp hair, a warning follows from behind: do not go out like that, or you will catch a cold. The recipient rolls their eyes because biology class taught a fundamental lesson: viruses cause disease, not cold weather. Three days later, a runny nose begins, and the family elder looks on with vindication. This exact scenario encapsulates a long running clash between traditional wisdom and modern science. The good news is that over the past decade, both sides of this debate have met in an unexpected place.

What causes the common cold?

The common cold is caused by a microbe rather than low temperature. Rhinoviruses account for the vast majority of cases, joined by a few coronaviruses and other respiratory viruses. These pathogens spread from person to person through airborne droplets expelled by coughing or by touching a contaminated surface and then touching the nose or eyes. Regardless of how cold a person feels, a cold will not develop unless the virus is present. Therefore, the assertion that getting cold causes illness is technically incorrect when taken literally.

The study that tested this belief most rigorously was published in 1968 by Douglas, Lindgren, and Couch. Researchers deliberately infected 44 volunteers who lacked antibodies against the specific virus with a rhinovirus and placed some of them in frigid conditions, keeping them in a room at 4 degrees Celsius or even immersing them in cold water. The cold exposure occurred at different stages of infection. The outcome was almost disappointingly clear: there was no significant difference in illness rates, symptom severity, or virus shedding between the chilled volunteers and those kept at normal temperatures. Even the title of the article was definitive: Exposure to Cold Environment and Rhinovirus Common Cold: Failure to Demonstrate Effect. For decades, the scientific consensus held that feeling cold had nothing to do with catching a cold.

Why do common colds spike in winter?

Yet a troubling question persisted beneath this definitive answer. If temperature plays no role whatsoever, why do cold cases spike during the winter months when schools close, workplaces empty out, and everyone has a runny nose? The explanation that people gather indoors more closely in winter, allowing viruses to spread more easily, explains part of the phenomenon but not all of it. This gap led researchers to look where the 1968 experiment did not: not at the virus, but at the host, specifically the defense line inside the nose.

The crucial detail here is that the interior of the nose is cooler than the rest of the body. While internal core temperature hovers around 37 degrees Celsius, the nasal cavity typically ranges between 33 and 35 degrees Celsius, dropping even further when breathing in cold air. It was already long known why rhinoviruses consistently colonize the nose rather than descending deep into the lungs: the virus prefers a cooler environment. In 2015, a team led by Ellen Foxman at Yale University asked a different question. What if the issue is not that the virus loves the cold, but that human immunity relaxes in cold temperatures? Foxman and colleagues published their findings in the Proceedings of the National Academy of Sciences.

How does cold weather affect nasal immunity?

The Yale team, led by Ellen Foxman, infected airway cells in the laboratory with a rhinovirus at two different temperatures: one at the internal body temperature of 37 degrees Celsius and the other at the cooler nasal cavity temperature of 33 degrees Celsius. The result was striking. As soon as the cells at 37 degrees Celsius detected the virus, they sounded a strong alarm, releasing abundant antiviral signaling molecules called interferons that suppressed viral replication. In the cells kept at 33 degrees Celsius, the same alarm was faint, allowing the virus to replicate more easily. Furthermore, the team demonstrated that this was not due to an intrinsic property of the virus itself, but rather to a weakening of the cellular defense response, as shutting down the immune signal allowed the virus to thrive even in warm conditions. Consequently, coolness affected not the virus, but the army responsible for confronting it.

A study published in 2023 by Huang, Taha, Nocera, Bleier, and colleagues made this picture even more concrete. A team in Boston discovered that nasal cells deploy a unique weapon against viruses: upon sensing a viral attack, they release billions of tiny extracellular vesicles packed with antiviral cargo. These vesicles act like a swarm of bees, with some carrying protective instructions to healthy cells and others offering themselves as decoys to prevent the virus from binding to actual cells. Researchers then exposed healthy volunteers from room temperature to a cold environment of approximately 4 degrees Celsius and measured an internal nasal temperature drop of about 5 degrees Celsius. When applying this temperature drop to cell cultures, the defense collapsed: the number of released vesicles dropped by about 42 percent, and the antiviral cargo and viral capture capacity within the vesicles declined. Ultimately, viral replication in the nasal cells nearly doubled.

Maternal wisdom can now be translated scientifically. The raw statement that getting cold makes a person sick remains technically incorrect because chilling alone cannot cause illness without a virus present. However, the statement that getting cold reduces nasal resistance against an encountered virus aligns with laboratory findings. Cold is not the primary cause of the disease, but it creates environmental conditions that weaken defenses at the exact moment a virus is encountered.

Can sudden chilling trigger cold symptoms?

There is another dimension to the issue where things become somewhat less certain. Ronald Eccles from Cardiff University proposed that chilling might not initiate a new infection, but rather awaken a virus already silently lingering in the nose. The hypothesis relies on the physiological reaction when feet or body surfaces suddenly cool down: blood vessels in the nose reflexively constrict, reducing blood flow and temporarily weakening regional defenses, which can allow a previously asymptomatic infection to manifest symptoms.

Eccles and his colleague Claire Johnson tested this in a 2005 study by dividing 180 healthy volunteers into two groups. One group had their feet soaked in cold water for twenty minutes while doing nothing else, whereas the control group sat with their shoes on in a dry container. In the following days, the group with chilled feet reported significantly higher rates of common cold symptoms, roughly one in ten participants. However, this study had notable limitations: symptoms relied on self-reporting by volunteers without actual viral testing, and those reporting colds turned out to be individuals who generally suffered from frequent chills throughout the year. Therefore, this single study alone does not prove the folk belief, though it does challenge the absolute claim that chilling has zero physiological effect.

Getting cold does not make you sick, but it can leave the door of your nose ajar at the unfortunate moment you encounter a virus. one sentence summary of this article

How should one protect against colds?

Putting the evidence on both sides of the scale, one fundamental truth remains on one side: the cause of the common cold is a virus, so the primary defense involves avoiding viral transmission. Washing hands frequently, exercising caution in crowded and poorly ventilated spaces, and staying away from others when sick are measures that unquestionably work. On the other side rests the final verdict of laboratory science: coolness genuinely slows down the immune army inside the nose. This does not mean living in fear of feeling cold, but it shows that staying warm during winter, protecting the neck and nose from cold air, and avoiding prolonged exposure while wet are logical habits rather than mere superstition.

Ultimately, maternal warnings were not entirely correct, yet they were not entirely wrong either. The assertion about catching a chill represented an intuitive observation passed down through generations that science long rejected before eventually validating parts of it. In the 2005 experiment by Johnson and Eccles involving 180 volunteers, participants who soaked their feet in cold water for twenty minutes reported common cold symptoms more frequently in subsequent days compared to the control group, demonstrating that cold weather does not introduce the virus itself, but rather slows down nasal defense mechanisms.

Notes and Sources

1. Douglas, R. G., Lindgren, K. M. & Couch, R. B. (1968). Exposure to Cold Environment and Rhinovirus Common Cold: Failure to Demonstrate Effect, New England Journal of Medicine, 279(14), 742-747. Cold exposure experiment with 44 volunteers finding no significant difference. ↩
2. Foxman, E. F., Storer, J. A., Fitzgerald, M. E. et al. (2015). Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells, Proceedings of the National Academy of Sciences (PNAS), 112(3), 827-832. Comparison of immune response at 33 degrees Celsius and 37 degrees Celsius. ↩
3. Huang, D., Taha, M. S., Nocera, A. L., Bleier, B. S. et al. (2023). Cold exposure impairs extracellular vesicle swarm-mediated nasal antiviral immunity, Journal of Allergy and Clinical Immunology, 151(2), 509-525. Weakening of nasal cell extracellular vesicles in cold conditions with an approximately 42 percent decrease in release. ↩
4. Eccles, R. (2002). Acute cooling of the body surface and the common cold, Rhinology, 40(3), 109-114. Hypothesis regarding surface cooling triggering symptoms via reflex vasoconstriction. ↩
5. Johnson, C. & Eccles, R. (2005). Acute cooling of the feet and the onset of common cold symptoms, Family Practice, 22(6), 608-613. Foot chilling experiment with 180 volunteers showing higher symptom reporting in the chilled group (13 out of 90 versus 5 out of 90). ↩