Originally Posted by DeepUnderground

At home I sleep without a shirt. On Cathay where its a bit warm, I've always just worn a very light weight under armor style gym t shirt with basketball shorts. On AA which has individual AC vents, I turn it on full blast and just use the AA long sleeve top and pajama pants provided and manage to stay cool. I haven't seen anyone shirtless before, I think it would be a bit odd in an airplane setting as some may be uncomfortable with that. Wouldn't bother me though.