A. Because a great quantity of air lurks entangled between their fibres; and air is a very bad conductor of heat.
Q. If air be a bad conductor of heat, why should we not feel as warm without clothing, as when we are wrapped in wool and fur?
A. Because the air (which is cooler than our body) is never at rest; and, therefore, fresh particles (perpetually passing over our body) keep drawing off the heat little by little.
Q. Why does the ceaseless change of air tend to decrease the warmth of a naked body?
A. Thus:—the air which cases the body absorbs as much heat from it as it can, while it remains in contact; it is then blown away, and makes room for a fresh coat of air, which does the same.
Q. Does the air (which encases a naked body) become by contact as warm as the body itself?
A. It would do so, if it remained motionless; but as it remains only a very short time, it absorbs as much heat as it can in the time, and passes on.
Q. Why do we feel colder in windy weather, than in a calm day?