Engine out practice

Jay:
In the future I think we'll practice slow flight (which mimics this
whole engine management procedure) before practicing engine-out
stuff. That should prevent the whole shock-cooling problem,
methinks.

Dale:
Slow flight might increase the problem. You're mushing along with poor
flow through the cowling, low airspeed and using power...perhaps you're
going to increase engine temp. over cruise.

That was my first thought, that slow flight would increase temp and,
therefore, how would it prevent the shock-cooling problem (if indeed it
is one)?