Hmmmm. Time for a re-post.
This is from July 2004 at
http://forum.officiating.com/showpos...1&postcount=27
Bedouins use black tents because they make a natural heat pump. The weave of the tent is loose. Hot air rises. What happens is the sun heats the black fabric and the air immediately surrounding the fabric. That air then rises to the top of the tent and exits through the loose weave. If air exits, more air must enter, so fresh air enters through open flaps in the tenp, creating a constant breeze.
The black robes follow much the same concept. By wearing loose black clothing, you end up with airflow even if there is no breeze.
White clothing does reflect more IR, preventing it from heating up as quickly, but it also reflects more UV light, causing uncovered areas of your body to be bombarded with UV from both the sun and the reflection. That's why you get sunburned easily while snow skiing.
And although white clothing doesn't heat up as quickly in the sun, the British army conducted experiments in WW2 that found after spending some time in the sun it doesn't matter what color you are wearing. All colors ended up at the same temperature next to the skin.
So if you wear some good interawear and a loose dark shirt, you will probably end up feeling cooler than if you wear light colors that reflect light.