Sounds like a good time was had by all.
I know the breeders of field labs get a lot of grief for the poor coats. But since training and trialing (or Hunt Testing) takes place year round, over-heating is almost a bigger liability than hypothermia while hunting in the fall. Probably explains why undercoat almost doesn't exist on either of my dogs. Hunters have taken to putting neoprene vests on their dogs as a result of the trends. (Although... some how, they seem to shed as much hair as any lab!??)
Even so, in the summer, we have to take every precaution and I think the black dogs suffer worse than the yellows.
What is the cool coat to which you referred?