I'm not sure if this has been posted before but I couldn't find it. I'm a little curious about hanging high in trees. I heard of a friend of mine who when they go hammock camping, they hang vertically above each other in trees. I know this is a dangerous method but I was just curious about how it's possible...

how would you get into / out of the hammock when there's no ground to rely one, just the hammock and a tree...?

Also, if there is a post or article about this anywhere, feel free to link to it