Ventilation and moisture

Having been a tenter since the age of 7, my folks were always camping somewhere, I remember those early days in my canvas pup tent with the sides you couldn't touch and the overwhelming feeling upon waking that it was too hot in there. For those who do not recall the old style kids pup tents were made of heavy canvas not windows and a zippered gnat door with heavy canvas flaps and canvas ties that tied when the flaps came together. They were waterproof, heavy and damp in mornings when you cooped yourself up in there.
I think of some of the teardrop designs even with one person may get a little "close" in there in the summertime. The folks who live in warmer climates especially have to deal with this problem, but I have been camping in Maine in summer with my modern three season tent and had the same problem. I have had an equally difficult problem tenting in the Delaware Water Gap of PA in early July being so hot I couldn't sleep in my tent with nothing but a 12volt can running sucking the tractor battery down to nill by midnight
How do you guys and gals handle having ventilation without electricity running a fan all night? That is besides of course opening your windows?
I think of some of the teardrop designs even with one person may get a little "close" in there in the summertime. The folks who live in warmer climates especially have to deal with this problem, but I have been camping in Maine in summer with my modern three season tent and had the same problem. I have had an equally difficult problem tenting in the Delaware Water Gap of PA in early July being so hot I couldn't sleep in my tent with nothing but a 12volt can running sucking the tractor battery down to nill by midnight
How do you guys and gals handle having ventilation without electricity running a fan all night? That is besides of course opening your windows?