It sounds counter-intuitive to me but twice (once in Germany and once in Atlanta) I have been told by salesmen that light-weight woolen dress pants are actually cooler in summer than cotton. The explanation given to me was that wool acts as an insulator and keeps out the summer heat. They insisted it was true no matter how hot the day. I have not, however, ever tried wearing them on warm --much less hot -- days. I am about to visit LAS and ATL in August, and have to decide between cotton and wool pants. The wool has the definite advantage of keeping a better press, so I would prefer it if I am not going to get baked inside. Has anyone here ever tried this? Was I told the truth or were the salespeople n both countries just telling me stories? Also, in ATL and LAS (the cities, not the airports) are sandals and shorts acceptable everywhere, includng better restaurants?