I have a flight planned from Boston to Hawaii (about 13 hours). I am normally fine on planes, but the longest I've traveled by plane is 4 hours.
I plan on giving blood (a normal whole blood donation, which I am also used to) about a week before the flight. Will that have a meaningful effect on how I feel during the long flight?
Just to be thorough, if I donated blood closer to the flight - say a day or a handful of hours before - would that affect me while flying? Is there any point at which it would be considered unsafe?