..hee...in fact, my helper also very careless sometimes, I noticed that she forgot that she was boiling the water...until all water vaporuised!!! Luckily I noticed it and turn off the fire immediately...she was scared as well...I now asked her to use the electric boiler rather then using the fire...you are right, we still need to rely on them to take care the BB, all we can do is to minimise the risk la...