Target the device at a metallic object, such as a firearm or sword, that you can see and is within range. Upon activation of the device, the targeted object will begin to glow red-hot, as the device transfers thermal energy to it. Any creature in physical contact with the object will take 2d8 fire damage at the point of device activation. For the duration of the effect, you may use a bonus action on successive turns to cause the damage again.   If the object targeted is being used as a weapon by a creature or is being worn, then they must succeed a CON saving throw, or else they drop the item (if the item can easily be dropped). If the object is not dropped, then the creature has disadvantage on attack rolls and ability checks until the start of your next turn.