I've done it all from -15F to 105F. MsNomer quote, "The van has wheels." is apt. I have an air conditioner but rarely use it and I have a van that I can operate and live (survive?
) in below zero conditions. We don't seek those extremes but they can happen by circumstances not under your control especially in the bridge seasons of fall and spring. We plan and practice most of our trips with the proverbial seeking the 70 degrees. Go north in the summer. Go south in the winter. Seek elevation of mountains and woods when it's hot or seek shore power.