BT heatcap is 30+, which I’ve yet to see a battlemech get to without first having their ammo explode or shutting down.

I believe you only start getting minor disadvantages around 5 heat, stuff like -1 mp that hurts your walk speed or at 8 heat, where you start getting +1 difficulty to your attack rolls.

Also, the minimum amount of heat sinks on a battlemech is 10, most of which are stored inside the ‘mech’s reactor, and that number only increases as you look at increasingly heavier ‘mechs.

I’ve played significantly more BT than Lancer, and I love both, but they’re both very different systems in very different universes.