I feel like this is a bias first world people have. I grew up poor, got plenty of haircuts from "a lady in the neighborhood" and never got chemical burns on my scalp, never had lice, etc. Sure, anecdata, but travel to basically any third world country where regulation is either nonexistent or unenforceable. Countless people do this every year. These things just aren't a real problem. You can get a haircut, you can get street food, etc. Basically just eat where the locals are eating and be careful about water/drinks that haven't been boiled. In other words, drink hot tea instead of water, or bottled stuff.