Do whatever you want. I keep my balls in the trunk. Usually keep them there the entire season. It's hot at the beginning of the season and I've had a couple of balls sweat out oil. I've had other balls that didn't seem to get hot at all. In the winter they stay out there and get cold. Never had an issue with any of them, although in the winter it seems the balls don't react as much until they warm up.
I've done the hot water bath and gotten good results on some balls and no results on others.
Remember to use a slow process on the balls to avoid cracking. You don't want to introduce a large temperature change. I've often wondered what would happen if you took a cold ball and dropped it in a bucket of hot water, or if you took a hot ball and put it in a bucket of ice water.
--------------------
Haywood
********************************************
"Let every nation know, whether it wishes us well or ill,
that we shall pay any price, bear any burden,
meet any hardship, support any friend, oppose any foe,
in order to assure the survival and the success of liberty."
--JOHN F. KENNEDY
********************************************