quick question re mass and energy

This is going to sound like a daft question but do objects, when they gain more energy, also gain mass?



The reason I ask is because of e=mc² . Energy is mass times the speed of light squared.



If energy increases then does mass? For example if I heated up a brick until it was red hot would it gain more mass?

via JREF Forum http://forums.randi.org/showthread.php?t=270542&goto=newpost