What exactly does the term 'ok' mean? As far as I am concerned, ok is all you can see through simply looking at the snake. I just do not see this working properly. Maybe for certain species of snakes, but with boids I really cannot see this working. It is just not the way nature made things, they bask to digest. Maybe its just me?
Also, MyKee, that whole thing on 'snakes absorb heat from their belly' kind of bothers me. When they are basking, they are getting heat from the sun are they not?