The assistant at this mobile barbecue stall (the child on the right)  is, as some residents of Yangon choose to do during a monsoon downpour, wearing a plastic bag over his head to prevent it from getting wet. Though I haven’t asked why, this likely has to do with the belief that if one’s hair becomes wet at certain times of the day or days of the week that one becomes more susceptible to illness.

What are comparable health-related beliefs in your culture/context? How do different people control for/deal with the same belief? Who markets to and profits from such beliefs, and how?