If it is cold out, I place the snake in a container which is, then, placed into an insulated box or cooler (with newspaper, or something else, to fill the empty spots and prevent snake container from sliding around inside the box or cooler).
A heat pack is added (Not against snake container) ... and measures are taken to ensure that the box/container does not become too hot.
However, if snake (box/cooler) is always in a warm place (during travel), a heat pack would not really be needed.
For warm weather, I do the same but, of course, do not add a heat pack. Cool pack may be added ... depending on certain circumstances.
Also, cold weather or warm weather, the insulated box (or cooler) is placed where it does not receive direct sunlight.