Do you have a history of high blood pressure? If not then it could very well be the heat and pregnancy. I had to get up slowly too. Actually I don't know anyone who could get up fast at the end of a twin pg!!
Also, I used to swell so bad on my hands, legs and feet that I had to put hot towels on legs at least once a day. If I put them up and put the towel down, it would relieve alot of swelling. With my hands, I tried to place them on my belly or somewhere where they were closer to my heart so they weren't always dangling. HTH
