I leave mine in the trunk of my car during bow season, and it's still sort of warm out then. I haven't had any trouble yet. Doesn't even get hot enough to melt the limb savers.

What is bad on them is direct sunlight and humidity. You do not want to leave it in a car with no case and have the sun hitting the bow thru the window. I don't know anyone that would do that though, for fear of getting it stolen.

I don't put my bow in a case most of the time either. I just put it in the trunk and throw a blanket over it.

Paul