The act of "boiling water" can refer to two things.

1. Heating up an amount of water with the intent to make it reach a temperature of 100 degrees Celsius, which is the accepted standard boiling point of water.

2. A euphemism for smoking weed (or another substance) through a bong, since the sound the water makes during inhalation resembles the sound of water that has reached it's boiling point.

1. Blue Monday is the most depressing day of the year, calculated by Dr. Cliff Arnall, a researcher at the University of Cardiff's Center for Lifelong Learning.
Factors used to calculate the date included weather conditions, debt level, time since Christmas, time since failing our New Year's resolutions, low motivation and feeling the need to take action.

In 2005 the date was calculated as January 24th, in 2006 it was January 23rd, and in 2007 it was January 22nd.

2. A song by the hard rock band Orgy from their album Candy Ass.