Same here, Bleu wears very well for me outside in humid, hot weather. I've never really tried wearing it when I was just pouring sweat, but outside of that, it's been one of the longer-lived frags.
I've never had that problem with Bleu de Chanel. However, I have found that as a native of the hot, humid southeastern U.S., I become anosmic to fragrances VERY quickly when I wear them in direct heat. I'll think they're gone but 3 hours later someone will tell me how nice I smell. I'd bet that's probably what happened with you
8/25/13 at 9:11pm