I suggest a permentaly mounted, Metal Tag or Sticker on the lid.
WARNING HOT SURFACE
Turn OFF Blower when re-fueling
Keep Lid properly sealed when in use
Also I am going to try the old flour and water mix for a seal to see how that works. The water evaporates out before the burn is completed, have to add water about every 2 1/2 hours.....
There does need to be locks or latches on the lid