We tested the theory that dark shirts are hotter in the sun. The way we tested this theory was to put the kids in both white and black t-shirts.
here. The kids were excited to see the results after standing in the sun and in the shade for 4 to 5 minutes.
Then we recorded their results on a chart and we were done! I love simple and easy science experiments that can be accomplished in one day. (Although if your child springs their science fair project on you at 10 p.m. the night before it is due.... this one won't exactly work! Not that THAT has happened to me before!!)