This can be caused by improper ventilation in a hot room or by having the cage located in an area where it receives direct sunlight. They should be kept in a climate of no more than 78 degrees. To help cool down your chinchilla immediately turn on a fan or the air conditioner and get the chinchilla out of that hot room. You can place some ice around the outside of the cage or put a bit of room temperature water on them. Make sure the chinchilla is offered enough water. You may even want to try some saline water or pedalite. Good signs that your chinchilla is undergoing a heatstroke you will notice them laying on their side, breathing fast, & bright red ears!.If you think your chinchilla is having a heatstroke try to cool it down slowly. I have found putting them on our basement floor cools them off nicely & fast. If you question their well being & your cooling method get them to a Vet ASAP!!!!!