Barefooters often have to listen to other well-meaning folks telling them that “You’re going to catch a cold.”
If I feel like a snippy response, it’ll often be: “Cold viruses don’t have eyes. They can’t look and see if I have anything on my feet or not.”
Yet, there does seem to be some sort of connection between being cold and getting colds. Colds are much more numerous in winter. There was even a study, “Acute cooling of the feet and the onset of common cold symptoms” that seems to show that chilling the feet can contribute to getting a cold. Actually, although the title refers to chilling the feet, the conclusion of the study is that a general chilling of the body that contributed to the cold; their suggested explanation was that chilling the body led to vasoconstriction of the blood vessels that inhibits the body’s ability to fight off the cold virus.
Unfortunately, much of the reporting on the study focused on the bare feet, not the chilling of the body. See here, for example.
In reality, it’s the chilling of the body that causes the problem. In addition, there is another, further explanation of how that chilling can make one more susceptible to the cold virus: cold viruses prefer cooler temperatures than body temperature. For instance, “An Explanation for the Seasonality of Acute Upper Respiratory Tract Viral Infections” notes that rhinoviruses (the cold virus) replicates best at temperatures quite a bit below body temperature. If the whole body gets chilled, lowering the temperature of the nose where the virus already happens to reside (but in check), that virus might then suddenly take off replicating and overwhelm the body’s defenses.
So, it’s not the cold feet, it’s the cold nose (that is brought about from chilling the whole body).
Thus, the secret of going barefoot in colder temperatures and not encouraging the cold virus is to keep the rest of your body warm. Make sure you are sufficiently bundled up, and the fact that you are barefooted should not make a difference in getting a cold.