(Answered) Heat after the heat phase

[Weirdo]

Total War, page 38.

They're rare, but situations do exist where a mech can take damage during the End Phase of a turn. Most show up in TacOps, though Total War has some for IndustrialMechs.

Since the End Phase takes place after the Heat Phase, am I correct in assuming that a heat-related critical hit(damage to engines, heat sinks, anything else I've forgotten) does not actually affect the mech until the next turn's Heat Phase?

[Xotl]

Sort of.  The specific effects of Heat caused by rising on the Heat Scale, as shown on the Heat Data Chart, are only applied during the Heat Phase, so regardless of when Heat Points are applied you'll never see their effect until the Heat Phase.  However, damage outside the Heat Scale caused by an unusual effect, even if heat-related, would generally be applied at the end of the phase it happened.

I would need to see the exact effects you're referring to in order to be certain.

[Weirdo]

Mostly I'm thinking about a unit that takes a critical hit to the engine during the End Phase.

[Xotl]

The damage is applied at the end of the phase.  But yes, since the damage effects are almost entirely related to heat output/dissipation, this effectively doesn't matter until the next Heat Phase.  It would only matter for things like tracking hits to engine shielding, if any (since a unit could take more hits to it before the next Heat Phase and be destroyed by this) and anything else non-heat point related.