When used, Scorch will use his hand to create a shield out of fire, similar to the Vortex Shield. It will stop incoming fire, and will damage enemies that get too close. It does a lot of damage, killing Pilots almost instantly, and does a lot of damage against Titans.
Trap an enemy into a corner with Thermal Shield, then deploy Incendiary Traps (this can be done while still using Thermal Shield) and light it on fire, dealing massive damage and probably destroying the titan.
Use it to kill pilots that have grappled onto you.
When a pilot is rodeoing you, back up against a wall, look straight up and turn on your thermal shield after a couple of seconds. When the pilot is forced off you, they should land in your heat shield, killing them almost instantly.