What we have delivered above, is nearly of universal extent: but some precautions are necessary for new incidents, and for the constitutions, sexes(21), and ages, and the seasons of the year. For it is neither very safe to remove from a healthy place into a sickly; nor from a sickly into a healthy. It is best to remove from a healthy place to a sickly, in the beginning of winter; from a sickly to a healthy, in the beginning of summer. It is neither fit to overload with food after much fasting, nor is fasting good after too full eating. And those persons endanger themselves, who, contrary to their custom, either once or twice a day eat immoderately. Again, sudden ease is very hurtful after great labour, and sudden labour after too great inactivity. For this reason, when one has a mind to make any change in his way of living, he must accustom himself to it gradually. All kinds of labour are more easily endured even by a boy or an old man, than by a man that is not used to it. And upon this account too, a life over inactive is not good; because there may happen to be a necessity for labour. But if at any time a person altogether unused has occasionally laboured, or even one, that is accustomed to it, has laboured much harder than ordinary, he ought to sleep with an empty stomach; and so much the rather, if he have a bitter taste in his mouth, or a dimness in his eyes, or his belly be disordered, For then he must not only sleep with an empty stomach, but even continue to fast the following day, unless rest has quickly carried off the disorder. And if that be the case, he should get up, and walk a little at a slow pace. But if a person has been at more moderate labour, so that he was not obliged to go to sleep, nevertheless he ought to walk in the same manner.