Many harsh chemicals like baby powder(which some adults use), deodorants, harsh chemicals in lotions and spray on colognes. Different things that are bad for your skin but many adults use everyday. <span />
~ B - Adding wood to a burning fire to increase the heat.
A is kind of like a reaction to negative feedback - it's too hot, so cooling down.
C is like turning the air conditioner off. It's cool enough.
B on the other hand adds something to the whole by reinforcing it. The fire is a metaphor for the writer's self-esteem, ego, good-feelingness, what-have-you.