I use them indoor and outdoor, the best about these being used outdoor is that the cables won't touch my faces, and I sweat a lot when walking outside (even from home to the train station in the morning). Here in Singapore it's hot and humid all year long, especially from April to June
Hi there fengwei, I'm also from Singapore and I do bring bring them out. But I don't listen to it until I settle down at my workplace to avoid funny looks and stares. And of course when I'm home. There's other phone that I use for when I'm out and about.