Do I bow back?

We landed in Bangkok some hours ago and stepped outside the airport's door. It was like sumberging in a warm, fruit soup. We went back inside and checked in to Koh Samui. Eating popcorn in Bangkok Airways lounge and blogging now, dizzy from the lack of sleep, from the humid air that does not follow the strict laws of air condition.

Question: do I bow back when Thai people bow at me? Anyone?