I don't know how things are in your neck of the woods, but it's cold here. It finally feels like winter has arrived. I read some Plutarch today, as a little pick-me-up. He was a Hellenic historian, biographer, and essayist, who later in his life became a Roman citizen and he wrote a lot about a lot of things. Of course, he also wrote about cold, in his "Moralia." Well, about the philosophy behind cold.

"Is there, then, Favorinus, an active principle or substance of Cold (as fire is of Heat) through the presence of which and through participation in which everything else becomes cold? Or is coldness rather a negation of warmth, as they say darkness is of light and rest of motion? 

Cold, indeed, seems to have the quality of being stationary, as heat has that of motion; while the cooling off of hot things is not caused by the presence of any force, but merely by the displacement of heat, for it can be seen to depart completely at the same time as the remainder cools off. 

[...] It is the nature of coldness, however, to produce affects and alterations in bodies that it enters no less than those caused by heat. Many objects can be frozen solid, or become condensed or made viscous, by cold. Moreover, the property whereby coldness promotes rest and resists most is not inert,
but acts by pressure and resistance, being constrictive and preservative because of its strength. This explains how, though negation is a disappearance and departure of the contrary force, many things may yet become cold while all the time containing within themselves considerable warmth.

[...] Furthermore, we find that cold can be perceived as well as heat; but mere negation cannot be seen or heard or touched or recognized by the other senses. [...] If, therefore, cold were a privation of warmth, we ought not to be able to feel it, but only to infer it from the deficiency in warmth; but if cold is perceived by the contraction and condensation of our flesh (just as heat is by the warming and loosening of it), clearly there is some special first principle and source of coldness, just as there is of heat.

[...] Is cold, then, so like this sort of privation that it produces no effects that differ? Or is the contrary true: Do not great and useful pleasures accrue to our bodies from the presence of cold, as well as mighty detriments and pains and depressions, before which the heat does not always depart and quit the field? Often, rather, though cut off within, it makes a stand and gives battle. This struggle of hot and cold is called shivering or shaking; and if heat is overcome, freezing and torpor set in; but if cold is defeated, there is diffused through the body a relaxed and pleasantly warm sensation which Homer calls "to be aglow." Surely these facts are obvious to everyone; and it is chiefly by these effects that cold is shown to be in opposition to heat, not as a negation or privation, but as one substance or one state13 to another: it is not a mere destruction or abolition of heat, but a positive substance or force. Otherwise we might just as well exclude winter from the list of seasons or the northerly blasts from that of winds, on the pretext that they are only a deficiency of hot weather or southerly gales and have no proper origin of their own."