THE TEMPERATURE OF LIVING-ROOMS.

By R. C. KEDZIE, M.D.,

MICHIGAN.

THE temperature of the air in a room in which a person is engaged in a sedentary occupation is a matter of importance because it is intimately associated with comfort and health. The living organism requires very different conditions from those in which inanimate objects may be preserved in safety. It has been said, "heat is life, cold is death." If any inanimate object, e. g., a bar of iron, is highly heated and then withdrawn from the source of heat, the temperature will rapidly fall till it reaches that of the surrounding medium, and will then fluctuate with the temperature of that medium. Not so with the human body, for it will maintain a nearly uniform temperature whatever may be that of the surrounding bodies. The fluctuations of temperature of the body as a whole are between 98° and 100° F. during health, and if the temperature of the blood falls much below, or rises much above, normal vital heat, disease and death are close at hand.

While the temperature of the body is nearly uniform, and usually high as compared with its surroundings, that of the air is ever fluctuating; and vigorous health is best maintained at a temperature much below blood-heat. In cold weather the dif ference between the temperature of the air and that of bloodheat is supplied either by heat supplied by oxidation and tissue changes within the body, or it must be supplied by heat from external sources. A certain amount of heat is produced by normal changes in the body, and if this is sufficient to make up the difference between the temperature of the air and bloodheat, the conditions of comfort and health will be fully met so far as temperature is concerned. But if the difference between. air-temperature and bodily temperature is greater than can be supplied by the internal heat produced by normal changes

taking place in the body, then the deficiency must be supplied either by heat external to the body, or by heat produced by abnormal changes within the body, and the conditions of health and comfort will not be fully met. The mode of life which makes frequent demands for internal heat by abnormal tissuechanges, so far from conducing to vigorous health, is making an inroad upon the capital stock of life, instead of simply expending the regular income.

The amount of internal heat naturally produced in the body is a fluctuating quantity, varying somewhat with the temperament, but especially with the amount of muscular exercise. Where, for any reason, bodily activity is restrained, the air must be correspondingly warmed to insure the conditions of healthy living. This condition demands consideration in the case of children, invalids, and those who follow sedentary occupations; and it is for these classes that I bespeak a careful consideration of the temperature of living-rooms.

PHYSICAL EXERCISE.

If a large amount of heat is produced by active exercise, the external supply is of less importance; thus we may work in comfort in an atmosphere at frost-point. But if the person is sitting still, and especially if the sedentary position is enforced, then the air of the room must be kept up to a certain temperature to secure comfort and health, and the more complete the quietude of the body the more nearly must the air-temperature approach that of blood-heat. The margin of safety for each individual between air-temperature and blood-heat, is the quantity of heat furnished to that person by the normal tissuechanges occurring in his body, which varies with his activity. Thus a teacher walking about the room may find the temperature agreeable to him, while it may be torture to a delicate child required to keep still. Moreover, the teacher has his " daily walk and conversation" in a warmer zone than the chilly floorlevel usually found in ill-ventilated houses in which the cold air on the floor is not swept away by ventilators opening at the floor-level.

Dr. Robert Angus Smith says: "Warmth must be obtained as the first demand of nature, and without it civilization will go back. When men are cold they give themselves to physical

exercise, and if that is impossible, to discomfort, in which the mind refuses to do more than to complain, if it cannot forget.' A teacher would probably regard it as a glaring innovation for his pupils to insist on taking enough physical exercise in a cold school-room to keep themselves warm, but the alternative in such a room is either active exercise or mental torpor in which "the mind refuses to do more than to complain."

For children, the feeble, and the physically inactive, a certain temperature is demanded in the living-room both for comfort. and safety. "To those who for any reason are incapable of withstanding and resisting its effects, cold is the great enemy of animal life, and the chief remote cause of human mortality: the effect of cold is most marked when the body is motionless."

The young have less capacity to resist cold than adults for two reasons: 1st, a small body has relatively a larger cooling surface than a larger body; and 2d, they have less power of resistance. These facts point to a higher temperature necessary in school-rooms than is required for adults in home life.

Some persons seem to look down upon bodily sensations as weaknesses, to be disregarded by superior minds, rather than counsels to be heeded; and to consider bodily comfort as having no intimate connection with health. But the sense of feeling was given us as the vidette of danger; it may have a look of bravery to disregard the signal shot of our vidette, but no good general will call it prudent. To live in continual discomfort is to be constantly exposed to disease.

THE HARDENING PROCESS.

Many persons think that one important part of the physical training of the young and the feeble is to harden them by exposure, so that they may endure heat and cold, storm and wind, without flinching, thus to produce a hardy vigor which shall ensure robust manhood and long life. They point with admiration to the sturdy forms and ruddy cheeks of the children of the poor, produced by enforced exposure in the open air, but speak pityingly of the pale cheeks and delicate forms of the children of the rich. But return in ten years and ask for those red cheeks, and you will probably find that one-half have paled in death from some acute disease, while the less vigorous but

'Marshall's Physiology, p. 877.

better guarded children of the rich mostly survive. The doctrine of the survival of the fittest," as applied to the young of our species, breaks down in ignominious failure if we consider this red-cheeked robustness the type of "the fittest." Excess of vigor usually ends in premature death. The Wingates, Heenans, and Morriseys die near the normal of noon of life, while the man of delicate frame often lives to his appointed threescore and ten. Call to mind the young men of your acquaintance who, at twenty, excelled in hardy vigor and were the athletes of their neighborhood, how many have passed into sound and vigorous old age? Perhaps the explanation may be offered that these persons trusted too implicitly to their stock of good health, and did not take prudent care to preserve it. But the fact remains that excessive good health differs but little from disease, and especially that form of superlative health secured by the training and hardening process. You may harden steel till it is nearly as hard as the diamond, but its natural elasticity is gone, and it is as brittle as glass.

Do not suppose that I undervalue vigorous health. Good health is the greatest physical blessing, and without it all other forms of physical good become useless toys. But this rude and boisterous vigor, which is often accepted as the highest type of health, is far from being its best exponent. In their extreme forms, coddling and hardening are alike to be avoided. In health, as in other things, the old maxim holds good, in medio tutissimus ibis.

LIVING BY THE THERMOMETER.

Sometimes a person will distrust his natural sensations, in respect to heat and cold, as untrustworthy guides, and betake himself to the thermometer as the only trustworthy indicator for temperature in living rooms. Some years ago I saw an article in the newspapers, in which an invalid, with weak lungs and a constitutional tendency to pulmonary disease, described his mode of life and effort to regain health in about the following words: "I live by the thermometer, not trusting my own feelings and sensations in a matter of so great importance. I keep my room, as nearly as possible, at the exact temperature of 60° Fahr., because this is the temperature for living rooms recommended by the best writers on hygiene. I exercise by walking in my room a good deal, and sometimes play the piano vigor

ously for more exercise. I take my meals at stated hours, avoiding all rich and stimulating food, and harden myself by a daily cold bath. Yet I am chilly most of the time, my health does not improve, I seem to grow a little weaker daily, and my lungs appear to grow worse rather than better. What shall I do more than I have done to regain my health?" Poor man! You are daily freezing to death, yet putting out the fire all the time. Get away from this chilling influence, if you have to break every thermometer in your neighborhood!

WHAT IS THE BEST TEMPERATURE FOR LIVING-ROOMS?

When we consult writers on hygiene, we find considerable diversity in the ideal temperature for living-rooms. As a rule, Europeans seem to be satisfied with a lower temperature than Americans.

De Chaumont says: "As a general principle the temperature of houses is kept too high. For a sitting-room under ordinary circumstances, a uniform temperature of 59° to 61° Fahr. (15° to 16° C.) is sufficient. In a work-room a lower temperature than 60° Fahr. is often desirable, and this applies both to manual labor and to head work." No one will dispute the statement that a temperature below 60° Fahr. is well suited to manual labor, but I seriously question his position in regard to the desirability of a lower temperature for head-work. Mere intellectual activity or brain-work produces but very little heat, and in a cold room the extremities of a sedentary person tend to become cold from deficient circulation of the blood, while the head and thoracic viscera become congested. I now speak of the brain worker as one who sits still for hours together without muscular exercise of any kind.

For school-rooms, Morin places the maximum temperature at 59° Fah.; Ficker, at 64° F., and Varrentrapp at 653° F. D. F. Lincoln, in an article on School Hygiene in Buck's Hygiene and Public Health, says: "School children can, beyond a doubt, be made comfortable at 66° F. (and even much lower, if accustomed to it), in a well-aired room." Here we find a difference of 7° between Morin's "maximum" and Lincoln's "comfortable."