The book reads as follows:

"...The Firebrand is the opposite of the Icedagger. "O! for a muse of fire, that would ascend the brightest heaven of invention." It is approximately 1.5x the size of the Linked Sword, and about twice as heavy [...], the handle a severe burn risk for those without gloves. By wielding the Firebrand, one can counteract those posessing the Icedagger, the blade's heat preventing one from freezing in the Icedagger's wake."

So basically all stuff you already knew.