Reddit mentions of Kaytee Chinchilla Chiller Granite Stone - 100079176

Keeping the room cool is the important part, but she may also be looking for some extra comfort after she's been particularly active. I know my guy likes to flop over on his granite after extended play times. Fortunately, they're pretty inexpensive, so it's probably worth trying one if you find some wiggle room in your pet supplies budget :)

You definitely want to cover any floors or shelves that have bare wires on them. It can cause bumblefoot, and that will be no fun for either of you. If you're concerned with the extra cloth making it too warm, you could get a space pod or some baskets for them to sleep in that won't be so warm. You could also get a chin chiller to give them a cool place to rest.

Many big name pet stores (Petco, Petsmart) sell this thing called a Chin-chiller. It's essentially a small piece of granite that by its nature stays cooler than room temperature. You can put it in their cage and they can lay on it to cool down.
https://www.amazon.com/Kaytee-Chinchilla-Chiller-Granite-Stone/dp/B000A7707O

Seconding the frozen water bottle with a hand towel.

You could get one of these small desk fans for like $8 and point it directly in their cage: http://www.walmart.com/ip/34136721?wmlspartner=wlpa&adid=22222222227023662628&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=c&wl3=53878145312&wl4=pla-101483560584&wl5=9008450&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=34136721&wl13=&veh=sem.

I don't recommend letting them splash around in the sink just because most rats really hate water and it will likely just stress them out like crazy.

They're adorable!! If they have trouble staying cool, you should get 'em some Chin Chillers, which we had for our chinchillas. They're slabs of granite you can put in their house that they can relax on and stay super cool in warm weather!

Buy 4 single tiles from your local hardware store. Keep one tile in the cage, one on standby and two in the freezer. The tile in the cage will always be slightly cooler than anything around it so the gerbils can spread out on it to cool themselves off. After a few hours, the tile will have absorbed the heat produced by your gerbils, so switch it out with the other tile on standby. If it gets really hot, pull out the tile from the freezer and push it against the outside of their cage or underneath it. This method may cause condensation within the tank, so look out for that and clean up afterwards. Replace the two freezer tiles with each other when one loses its cooling powers.






Here is what they sell at pet stores marked up slightly higher than hardware stores :
https://www.amazon.com/gp/aw/d/B000A7707O/ref=mp_s_a_1_1?ie=UTF8&qid=1524225481&sr=8-1&keywords=chinchilla+tile





Also, your gerbils will pee on the tile often. Easy to clean up. I've noticed gerbils like to pee on smooth surfaces. If you put an empty mason jar in one corner of the cage, and clean it out 2+ times a day, they will learn to pee in that Mason jar instead of on the tile. Potty Trained gerbils!

We have a chinchilla and live in NE Indiana near the Michigan border. We keep our thermostat at 65-68 in the winter when it snows and he is fine. We have also bought some cooler granite boards for his cage that he can lay on if he gets too hot. I have provided a link for that below. In the summer we usually keep a small fan near his cage so he can cool off if he is too hot. http://www.amazon.com/Kaytee-Chinchilla-Chiller-Granite-Stone/dp/B000A7707O/ref=sr_1_fkmr0_1?ie=UTF8&qid=1418139765&sr=8-1-fkmr0&keywords=chinchilla+cooling+board

the pet store i work at sells cooling stones for chinchillas so maybe look into getting one of those? i honestly think it could work super well and it’s relatively cheap if it doesn’t work out but i’ll link it: cooling stone

If it feels cool when you touch it, and stays cool as you hold your fingers to it, then it has a high heat conductivity and is capable of pulling heat away long term. Some ceramics have a high heat conductivity and some don't. I have one of these , which works very well:

https://www.amazon.com/Kaytee-Chinchilla-Chiller-Granite-Stone/dp/B000A7707O

Granite is a really dense rock (not a ceramic) that has a high heat conductivity.

Also, I want to say this clearly for the OP and others - a cooling rock is NOT going to give your chinchilla the ability to exist happily at 86 fahrenheit. It doesn't do enough. It shouldn't be considered as widening the range of temperatures that chinchillas can live in. This is a stopgap measure in an emergency, or a cage fitting for the chinchilla's comfort the rest of the year, no more.

some pet stores actually sell marble slabs or granite stones for chinchillas http://www.amazon.com/Super-Pet-Chinchilla-Chin-Chiller-Granite/dp/B000A7707O/ref=cm_cr_pr_product_top

but you can sometimes find a extra pieces from construction/home remodel projects and the owner would let go of a few scraps/pieces for free. :)