While it has been discussed many times about storing coins and indoors temperature, I don't remember a thread about outdoor conditions. For example, you buy a coin on ebay or someplace else, and it is being shipped to you. Outside the temp is way below freezing, so your coin will be shipped from a warm place, then travel for days in the (extreme) cold, then back in the indoor warmth. Could this harm the coin?
Maybe, if it's in such a tight enclosure that differential expansion would put pressure on it, but that's really far-fetched. The biggest danger is probably condensation. If it's packed in Florida humidity, and then shipped to Nebraska... but even then, there's very little air trapped in the packaging, and therefore very little moisture. If you get a cold package and open it in a humid environment, you can get condensation. If your house is humid, let the package warm up before you open it.
I doubt it is something you have to worry about, but if you leave a slabbed coin in a hot car then you may have a problem.
Yes, condensation is what I'm talking about. I don't have any evidence, but I think proof coins are more likely to develop that. I don't own a cheap proof coin, but if someone has got a regular proof quarter or something worth close to face value anyway, maybe you can leave it outside in the cold for a while, then take it back inside. Try this with just the coin at first, then try with the coin inside an airtight holder. I have had metal items (not coins) arriving full of condensation, lots of it.
On my latest US Mint shipment (3 PF ASE's), I noticed one of them looked to have condensation (mild at best) inside the airtite. I pried it open to let it "dry". I didn't want to take any chances.
Condensation is certainly possible, but I've bought coins over a period of 50 years in slabs, Air-Tites, flips, just about every coin holder you can imagine, and never had a problem with condensation. Does that mean you won't ? No, just means I never did, over a long period of time.
When bringing in coins from the cold, allow the package containing them (bubble mailer, 2x2, air-tite, flip, tube, box, etc.) to reach room temperature before opening it. Otherwise you risk having condensation form on the coin itself, which you want to avoid.
C'mon John, that's the logical thing to do! Sometimes I just can't wait! How many licks does it take to get to the center of a tootsie pop? All kidding aside, you're advice is sound. I also agree with Doug about not having problems, but I didn't want to take the chance when I noticed some mild condensation inside the airtite.
Condensation is just distilled water. Unless you live somewhere where the environment is polluted to the point of being a serious hazard to health.
