there is a thread here on rounds cooking off in a house fire that i found pretty informative. I too was worried about this issue since i can not carry while on the job, i have to leave my guns in my car. i usually just leave them in the glove box or in a hard case. but do a search and see what you find. I have not had any issue so far. I would not, however, leave a holster in the car. Most Galco holsters have instructionals that say not to, plus the glue on my ankle holster has gotten a little sloppy after leaving it in the car a few too many times. I always think of the mythbusters episode where they leave the car out in the sun to see if the biscuit cans explode. I dont think cars can really get hot enough to cook off rounds.