There is one realm, however, where the swing of this ancient superstition vibrates with fullest intensity, and that is in those diseases which, as their name implies, are still believed to be due to exposure to a lowered temperature—"common colds." Here again it has a certain amount of rational basis, but this is growing less and less every day. The present attitude of thoughtful physicians may be graphically indicated by the flippant inquiry of the riddle-maker, "When is a cold not a cold?" and the answer, "Two-thirds of the time." This much we are certain of already: that the majority of so-called "colds" have little or nothing to do with exposure to a low temperature, that they are entirely misnamed, and that a better term for them would be fouls. In fact, this proportion can be clearly and definitely proved and traced as infections spreading from one victim to another. The best place to catch them is not out-of-doors, or even in drafty hallways, but in close, stuffy, infected hotel bedrooms, sleeping-cars, churches, and theatres.
Two arguments in rebuttal will at once be brought forward, both apparently conclusive. One is that colds are vastly more frequent in winter, and the other that when you sit in a draft until you feel chilly, you inevitably have a cold afterward. Both these arguments alike, however, are based upon a misunderstanding. The frequency of colds in winter is chiefly due to the fact that, at this time of the year, we crowd into houses and rooms, shutting the doors and windows in order to keep warm, and thus provide a ready-made hothouse for the cultivation and transmission from one to another of the influenza and other bacilli. As the brilliant young English pulmonary expert, Dr. Leonard Williams, puts it, "a constant succession of colds implies a mode of life in which all aërial microbes are afforded abundant opportunities." At the same time, we take less exercise and sit far less in the open air, thus lowering our general vigor and resisting power and making us more susceptible to attack. Those who live out-of-doors winter and summer, and who ventilate their houses properly, even in cold weather, suffer comparatively little more from colds in the winter-time than they do in summer; although, of course, the most vigorous individual, in the best ventilated surroundings, will occasionally succumb to some particularly virulent infection.
The second fact of experience, catching cold after sitting in a draft or a chilly room until you begin to cough or sneeze, is one to which a majority of us would be willing to testify personally, and yet it is based upon something little better than an illusion. It is a well-known peculiarity of many fevers and infections to begin with a chill. The patient complains of shiverings up and down his spine, his fingernails and his lips become blue, in extreme cases his teeth chatter, and his limbs begin to twitch and shake, and he ends up in a typical ague fit. The best known, because most striking, illustration is malaria, or fever and ague, "chills and fever," as it is variously termed. But this form of attack, milder and much slighter in degree, may occur in almost every known infection, such as pneumonia, typhoid, tuberculosis, scarlet fever, measles, and influenza. It has nothing whatever to do with either external or internal temperature; for if you slip a fever-thermometer under your chilling patient's tongue, it will usually register anywhere from 102 to 105°.
This method of attack is especially common, not only in influenza, but also in all the other so-called "common colds." In fact, when we begin to shiver and sneeze and hunt around for an imaginary draft or lowering of the temperature which has caused it, we are actually in the first stage of the development of an infection which was contracted hours, or even days, before.
When you begin to shiver and sneeze and run at the eyes you are not "catching" cold; you have already caught it long before, and it is beginning to break out on you. Mere exposure to cold will never cause sneezing. It takes a definite irritation of the nasal mucous membrane, by gas or dust from without, or toxins from within, to produce a sneeze.
As to mere exposure to cold weather and wet and storm being able to produce it, it is the almost unanimous testimony of Arctic explorers that, during their sojourn of from two to three years in the frozen North, they never had so much as a sneeze or a sore throat, even though frequently sheltered in extemporized huts, and running short of adequate food-supply before spring. Within a week of their return to civilization they would begin sneezing and coughing, and catch furious colds.
Lumbermen, trappers, hunters, and prospectors in Alaska give similar testimony. I have talked with scores of these pioneers, visiting them, in fact, in their camps under conditions of wet, cold, and exposure that would have made one afraid of either pneumonia or rheumatism before morning, and found that, so long as they remained up in the mountains or out in the snow, and no case of influenza, sore throat, or cold happened to be brought into the camp, they would be entirely free from coughs and colds; but that, upon returning to civilization and sleeping in the stuffy room of a rude frontier hotel, they would frequently catch cold within three days.
One unusually intelligent foreman of a lumber camp in Oregon told me that an experience of this kind had occurred to him three different times that he could distinctly recollect.
It is difficult to catch a cold or pneumonia unless the bacilli are there to be caught. Boswell has embalmed for us, in the amber of his matchless biography, the fact that it had been noted, even in those days, that the inhabitants of one of the Faroe Islands never had colds in the head except on the rare occasions when a ship would touch there—usually not oftener than once a year. Then, within a week, half the population would be blowing and sneezing. The great Samuel commented upon the fact at length, and advanced the ingenious explanation that, as the harbor was so difficult of entry, the ships could beat in only when the wind was in a certain quarter, and that quarter was the nor'east. Hinc illæ lacrimæ! (Hence these weeps!) The colds were caused by the northeast wind of unsavory reputation! How often the wind got into the northeast without bringing a ship or colds he apparently did not speculate.
To come nearer yet, did you ever catch cold when camping out? I have waked in the morning with the snow drifting across the back of my neck, been wet to the skin all day, and gone to bed in my wet clothes, and slept myself dry; and have lain out all day in a November gale, in a hollow scooped in the half-frozen ground of the duck-marsh, and felt never a hair the worse. Scores of similar experiences will rise up in the minds of every camper, hunter, or fisherman. You may catch cold during the first day or two out, before you have got the foul city air, with its dust and bacteria, out of your lungs and throat, but even this rarely happens.