Congratulations :)
In the past, I have played escape games where the only hint of a future fire's location is a discoloration of the sand set to a clickable location with the message "You could start a fire here," so I had not thought of making the fire location more prominent. However, I think it is a good idea and when the jam is over, I am definitely going to. I think I will place the log there and have the player gather some dry grass from the woods to use as fire starter.