Originally Posted by Juha

If it's been raining for a couple of days in a row, and you've been camping all that time, odds are your tent is getting wet from the inside too. Heat some (large) stones to scorching hot in campfire, then use sticks or something to roll them into an empty camp stove kettle. Carry the kettle in your tent, set it up in the middle of the tent floor. Be careful not to burn tent floor or walls. I use Trangia windscreen for support, it also prevents kettle from tumbling over. Leave it there for a couple of hours, make sure that you have some ventilation in the tent. The heat source will dry the inside of the tent (or inner tent entirely, if you have double wall tent like I do) . It's not enough to dry a sleeping bag completely, but will help there too.

I suppose if you have a couple of kgs of hot stones and a pan large enough, you can make a portable sauna like this!

(Actually tent saunas are great and have been around for a long time. I wouldn't try it with a normal tent though.)

--J