I can’t seem to find anything in the book about suggestions for handling environmental hazards. I first started thinking of it when I was thinking about a green dragon. A green dragon would breathe a cloud of poison gas that would stick around for a while. A similar thing could apply to a red dragon though. It could set the ground on fire. It could also set characters on fire. Black dragons acid would have similar ongoing harmful effects.
What are some good ways to handle these environmental hazards—especially when they’re applied directly to a character like being on fire or covered in acid?
Not running through a field of flames is obviously defy danger.
Standing in a room filled with poison gas would be defy danger to hold your breath, but how frequently should they be rolling it?
How frequently should a player on fire take damage? Each time they do something other than successfully put out the flames?
What about a building on fire collapsing around the players?