We leave our dog in our small motorhome all the time in warm weather with the A/C running.
However as backup we also leave the rear and front vents open, with the front vent fan pushing or pulling air on HIGH so as to provide maximum airflow throughout the length of the motorhome just in case the generator should ever quit for whatever reason.
NOTE: For the first time ever ... this January in Arizona we left the dog in the motorhome in 80 degree weather and when we came back the GENERATOR HAD QUIT ... but the backup roof vent approach I mentioned above had managed to keep the interior no hotter than about 80 degrees. This incident has cost me sleep ... the generator immediately afterwards, and now, starts and runs fine ... why on Earth did it quit in Arizona at the wrong time? (The motorhome had plenty of gas in it's tank at the time.)
