Upside down [open]

Regan was from enough from camp that she could have a peaceful moment to herself, but close enough that if something happened she could be found quickly. In fact, she was in a tree twenty feet from the camp.

She wanted to see how long she could hang upside down before she got woozy.

As she felt her had starting to get light, she swung back up, sitting up straight, making the world wobble. Not long, and she went up to fast. Lovely.