Best way to heat a neck without fancy tools

[Busker]

I have an old bass, only paid $40 for it and its not worth much, so if I mess it up, no biggie (but of course, I'd rather fix it then mess it up).

The neck has a slight sideways bow. When you sight down the edge of the fretboard, you can see the treble side curve in slightly, and the bass side bow out. It makes for the G string to be a little close to the edge of the fretboard for a little way down the neck. Not bad, but its noticeable to me.

I guess I can live with it. The bass is playable. But I thought maybe I could heat the neck and pull the bow out with clamps and blocks. The wood has to get pretty hot to be workable, right?

Best way to heat a neck at home with no fancy guitar neck heater upper thingie?