Prepare your work surface, arranging the equipment you will need before soldering. Make sure the soldering and brazing mat you use is capable of withstanding the correct solder temperature.
If you’re using a blow torch, avoid directing the flame at the mat. This will cause the mat to shrivel up, reducing its thermal properties and thus letting heat go through it.
Furthermore, it could cause irreparable damage to your work surface.
If the fabric should happen to glow where heat has been concentrated on one particular spot, then rearrange the mat to let any unheated areas be used instead.