It wasn't awful, but my DH got his on his calf and having his leg down for an 8 hour flight, and then a 2 hour flight, he was a little swollen. That was the only issue. We live in Ohio, so we flew from Cleveland to Houston, then from Houston to Oahu. We plan to go again, and will NOT fly into Houston, or Atlanta, it will be LA or Seattle, or something as far west as possible, LOL.
Mine was on my ankle, like I said, but I'm smaller than DH so I didn't have any issue moving around and I didn't swell as much. A little, but nothing an extra bottle of water and an aleve didn't take care of!
I think its a GREAT idea, Veal. Really. You won't regret it! Not only is it to remember your husband and marriage, you can always say 'oh, yeah, I got this in Hawaii!' ... I don't know where you are in the Midwest, but people here are like, oooo! hawaii!
