I think I saw this addressed somewhere but now I can't find it.

Today in the practice both me and the other gal experienced dizziness after the swim.

Does anyone know
A. what causes it
B. can it be avoided and if so how
C. If it can't be avoided how is it worked around

Is it different in different bodies of water or different temps? - we were in a 64 degree river.

Any and all help in this matter will be greatly appreciated.