Must Read and See the Demo!
A 26-year old person decided to have a cup of coffee. He took a cup of
water and put it in the microwave to heat it up (something that he had
done numerous times before).
I am not sure how long he set the timer for, but he told me he wanted to
bring the water to a boil. When the timer shut the oven off, he removed
the cup from the oven. As he looked into the cup, he noted that the water
was not boiling, but instantly the water in the cup "blew up" into his face!
The cup remained intact until he threw it out of his hand but all the
water had flown out into his face due to the build up of energy. His whole
face is blistered and he has 1st and 2nd degree burns to his face which
may leave scarring. He also may have lost partial sight in his left eye.
While at the hospital, the doctor who was attending to him stated that
this is fairly common occurrence and water (alone) should never be heated
in a microwave oven. If water is heated in this manner, something should
be placed in the cup to diffuse the energy such as: a wooden stir stick,
tea bag, etc. It is however a much safer choice to boil the water in a
tea kettle.
http://media.putfile.com/superheating