Storing kits

I left a kit in my truck a few weeks ago in 105 degrees outside temp. Not sure what the temp on the inside of the truck was but the kit was undamaged. But this was only for one day, not a prolonged period.

I wouldn't—and don't. High heat can do at least two things to styrene: it may warp, but worse, it will get more brittle. The high temperatures drive plasticizers out of the plastic over time, making it more brittle. These plasticizers may have an adverse effect on your decals. And such exposure could completely destroy some vinyl components.

I sure wouldn't use the attic.

I left a couple empty cassette cases on the back seat of my car for about a week and they now look like pieces of abstract art. Definitely won't hold a cassette tape anymore. 

First off Jeremy, to the forums Glad to see another Nor Cal boy in here
Being from Stockton myself I can definately say Don't store the kits in the attic I had to crwal through mine during the 110 temps to fix the cable wire & looked in a footlocker I have up there. My plastic protractor, compass & ruler set were ruined I was looking for them & that's where I found them. It was like 150 degrees in there that day.
Is your garage air conditioned?

Peace,
Eddie

Jeremy, I'm rebuilding a store (old farm stand) into a hobby shop up here in NH. The temps can go from -35º to 110º in the building. So I contacted my distributor regarding storing of my kits. They told me - "If it's comfortable for me to spend extended time in the room, it will be fine for the kits, -35º and 110º are definitely too extreme." They told me the best temp range is between 50º & 80º plus or minus an 'occasional' 10º fluctuation.

So now I'm planning out the heating and ventilating system.