Overheating will generate negative effects that worsen the longer you stay over the red line.
Guts reduces the chance of shutdown/ammo explosions.
"ShutdownPercentages": [0.083, 0.278, 0.583, 0.833], (chance of shutdown)
"AmmoExplosionPercentages": [0, 0.083, 0.278, 0.583], (chance of your ammo going boom)
"HeatToHitModifiers": [1, 2, 3, 4], (less accurate with weapons/melee)
"OverheatedMovePenalty": [0.1, 0.2, 0.3, 0.4] (unit moves slower)
a 1 on the chances implies a 100% chance
The above means that your first turn of overheat is free in terms of your ammo not exploding. The same applies to your enemies if you're into putting them to "sleep" (shutdown) with inferno ammo and other various heat generators.
Going back under the redline resets the chances and the whole process restarts.
RogueTech has been updated to use tabletop-like double heatsink rules for Internal Engine heatsinks. If you use said Heat sink kit (D) the 10 minimum heatsinks (i.e. 8 in the engine, 2 in your random slots) need to all be double, or you don't get the full benefit and use more tonnage.
You can also use a heat sink kit (D) to upgrade the heat sinks in the engine itself. Expensive, but highly beneficial to your hot dogs if you can find one.
Heat banks and exchangers do not stack by type, but they do stack by quality.
This allows the distinction between using chassis with heatbanks and exchangers, improving several aspects of the chassis, or to go for simple raw dissipation.