Have you ever been in one of the following situations?
If you've ever been in situation like those mentioned above, then there is a good chance that you have also experienced that light headed
feeling that comes from being in a stuffy environment
with no chance of moving around to get some circulation
Well here is a tip on how to cope. Wiggle your toes vigourously. I kid you not.
This tip was passed on to me by an Army friend of mine. He said that when they have to stand at attention for long periods of time in the sun (like on parade or inspection), they were told to wiggle their toes periodically. This forced their blood to circulate around their body and prevented the soldiers from fainting.
Try it, you'll find it helps!