I'd rather not know what sort of fumes rise off a circuit board when broiling it with a heat gun or taking it out of a hot oven.
Shouldn't be much in the way of fumes. The circuit board goes through a similar process at manufacturing time. After that, the board is washed to remove excess flux and other gunk. Assuming the OP didn't leave any stickers or such on the circuit board, it should be fine.
As a note to anyone thinking to do something like this... you should only try to reflow the board itself. Take everything apart. Do not, under any circumstances, heat up any kind of battery, or else bad things will happen.
Shouldn't be much in the way of fumes. The circuit board goes through a similar process at manufacturing time. After that, the board is washed to remove excess flux and other gunk. Assuming the OP didn't leave any stickers or such on the circuit board, it should be fine.
As a note to anyone thinking to do something like this... you should only try to reflow the board itself. Take everything apart. Do not, under any circumstances, heat up any kind of battery, or else bad things will happen.