What sort of overheating? Are you referring to oil temps?
In very hot conditions, I have seen oil temps start to get too high. The key is to keep forward flow through the engines. If you are in flat pitch, then it can be an issue. I suppose with the start locks on, it would particularly be an issue-- I haven't experienced that. But I do remember long taxis in 100+ degree weather where we ran into the heat issue, and again, the key was just to keep forward flow through the engines.