It's a wire crate so there's plenty of circulation. We do keep a towel over the top (not blocking where he breathes) as the basement is about 52 degrees and I'm a little concerned about joints. Jake, our other springer, sleeps next to him in his crate and does not have the same issue.
Crate doors are closed so they don't go out and explore at night and get into something they shouldn't. We are very diligent in reducing that risk but sometimes spit happens. I feel the risk of other issues outweighs the risk of a fire. After watching my BIL's cocker suffer from eating a battery and having one of our Gordon's get wrapped in a venetian blind cord I am a firm believer in crate training. Every vet I've had has agreed. My previous dogs also used to sleep on the bed but they were bed hogs!
I think I will look into a fan to keep air circulating. We are having the heat hooked up down there in a few weeks but only plan on keeping it around 60.
Dr. Doug, if you read this, your thoughts on dogs sleeping in 52 degrees as it relates to joint issues. Jake, who already has bad hips, just turned 10 and Jesse will be 10 in April. Thanks.