Not well. The Berner has such a heavy coat, that he/she would need to remain indoors for most months out of the year.
My berner doesn't like the hot weather at all. He does love the outdoors, though, so I wouldn't consider moving to Florida with him.
Learn what to do if they over heat. You'll also have to give them alot of water.
what if the weather gets really hot a couple days would a bermese mountain dog be okay???
Do what I do. RUN him in the morning before it gets hot. Walk and train in the evening. Walk them once more at night just before it gets totally dark. I have a Samoyed and live in a very hot place, but she does fine in the summer. In the winter, she can play all she wants outside.
Try shaving the abdomen to decrease heat conservation and keep the remaining coat well groomed and trimmed.
I disagree. they would be fine if you don't feed them too much ( so you won't have to exercise them too much) and keep them from being overheated.
We shave our Bernese during the summer-- we leave his head and tail long. But he still looks really cute, and is much happier. And once it gets cold outside, his hair grows back as if we'd never shaved it.