I did a tandem a number of months ago. Was having an amazing time until the chute opened. Almost immediately I felt the symptoms of what I thought was motion sickness. Pretty soon afterwards I felt lightheaded, started seeing spots, back of neck hurt. Next thing I know I'm waking up in the grass.
For the rest of the day I had a pounding headache, and my lower body hurt.
I'm in my twenties, am a runner, well within normal height, and weight and have no medical conditions that would have caused this issue.
The only thing I can think of is I probably had an very light breakfast when I woke up at 8 am, ate nothing in between, and jumped at around 1 PM.
I'd love to go through AFF and beyond but after this experience I'm hesitant.