Hot glue guns are great at joining most materials together easily and sturdily ,but if you're using very sensitive materials, the heat of the hot glue can damage the material. If you encounter this problem, you can wire a standard light dimmer switch to control the temperature of the glue.
Instructables user Andygadget came up with this hack after ruining several sheets of Depron foam in making remote-controlled model aeroplanes. Full wiring instructions can be found at the source link below and the author also suggests using a project box to enclose the dimmer switch for safety.
Make your hot glue gun cooler [Instructables]