Chinchillas are native to a cool, mountain region. Their coats are thick and plushy to protect them from the harsh natural elements in such a region. Humans have domesticated chinchillas, but they are still adapted to their wild habitat rather than our own. Any owner must keep this in mind when caring for a chinchilla.
Optimum temperature for a chinchilla is between 60 and 70 degrees fahrenheit with low humidity. Generally speaking, they can temporarily tolerate up to about 76 degrees, but 72-73 is about the highest recommended temperature. Basically, if you're comfortable in a thick winter sweater, they'll be comfortable. Keep this in mind at all times.
Danger sets in at much over 78 degrees. A chinchilla cannot effectively cool itself like humans and other animals can. Humans sweat and dogs pant; the only defense a chinchilla has is to increase blood flow to it's large ears, which is cooled by the air and recirculated through the blood stream. This is not an effective cooling system in extreme temperatures and a chinchilla can quickly overheat. You as a guardian must take measures to prevent this.
Air conditioning is always recommended when temperatures can reach above 75 degrees. It's really the only sure way to keep chinchillas comfortable and safe during warm days.
In the event that your air conditioning would go out, there are several
measures you can take to keep your chinchillas cool short term. Keeping
a number of backup cooling agents on hand can buy precious time for chins
in danger. However, they are not long term solutions - if you expect to
be without air conditioning for more than a few hours, relocate the chinchillas
to an air conditioned area.
Cooling Items kept in the freezer:
Terra Cotta (pipes, pots, chimineas)
Ceramic floor tiles
River Stones (rounded edge rocks, found in garden departments)
Other temporary cooling methods can be used, such as a pan of ice with a fan blowing over it. Do not point the fan at the chinchillas directly, however. Keep in mind that heat rises and cold falls, so you want the air flow pointed up rather than down.
In the event that your chinchilla is overheated, contact your veterinarian or qualified emergency vet immediately. If you're able, get a rectal temperature using a digital thermometer and a little bit of lubricant. Over 103 is a danger zone. Start taking measures to cool the chinchilla while you're on the phone. A wet towel (not ice cold) wrapped around him to wet the skin can help to cool the chinchilla. Do not use an ice pack, as ice will close the blood vessels too quickly to effectively cool. Have cool air blowing over the wet skin to evaporate the water and thus cool the chinchilla. Stop cooling efforts when the body temperature reaches 103, as the body will continue to cool, and the chinchilla can actually have it's temperature dip too low.
It's preferrable to do this on the way to the vet. Even if you get your chinchilla cooled off, there are complications that can arise from heat injury that will need to be addressed by a qualified veterinarian. I would advise any chinchilla subjected to heat injury always be seen by an experienced exotic veterinarian.
Chinchillas can rapidly get into dire trouble when heat is involved. Taking steps to prevent this situation as well as knowing how to handle potential issues is your chinchilla's best defense against a natural enemy. Your chin will thank you for saving it's life.