I haven't stayed in a cave but I did spend a week in an abandoned railroad tunnel (abandoned to the point that some of the rails had been removed). Lots of airflow but that's both good and bad. Gets cold at night but I don't have to worry about lighting up a fire. The hardest part is the cold ground.... some sort of pad is essential. Other than that... I build a windbreak out of some wooden pallets and was good to go.