As Lloyd and Garmadon are being carted toward the volcano, one of their captors claims that the 15 million Kelvin temperature lava will melt them before they even feel the heat. While technically true, volcanic lava is not anywhere near that hot. Volcanic lava can be anywhere from 970 to 1500 Kelvin (700 to 1200 Celsius.) By comparison, 15 million Kelvin is roughly 15 million Celsius and is the approximate temperature of the nuclear core of the sun. If the volcano was really 15 million kelvin, everything around it would be vaporized.