The origin of one-day fevers is traced either to mental states, or to bodily states, or to things coming from outside. Fevers that depend on mental states are fevers from grief, from care, from thinking, from anger, from insomnia, from sleep, from joy, from fear, from fatigue, fevers that arise from physical states, or depend on circumstances that are actions, movements or things opposite to them, or do not come from actions, movements or something opposite to this. Fever due to fatigue, idleness or defecation depends on circumstances, which are movements or what is opposite to them; These also include one-day fevers from pain, one-day fevers from fainting, from hunger or thirst. Fever that is independent of action includes those due to blockages, indigestion, swelling, or roughness of the skin. As for fevers attributed to things coming from outside, these are, for example, fevers from sunburn or, for example, from cold, hardening of the skin or ablution.