Burners are Silvers who can manipulate heat and fire. They require a spark, usually from special bracelets, to enable them to manipulate their element.
However, there are also newbloods who can create fire, without the aid of flame bracelets.
Usually burners wear flameproof clothes, so that when they are using and controlling flames, their clothes can hold in one piece.
"Burners are elementals, manipulators of fire and temperature, although open flame requires an existing spark or separate flame to feed from. Burners are best known as the scions of House Calore, the dynastic rulers of Norta for over three hundred years." -Victoria Aveyard, "War Storm" "On Silverblooded Abilities"