Thought I'd give "Pre-Cooling" a try so had an ice-cream and chilled water before going out for run 2 of week 9 this evening.
Whether it was the pre-flight meal or running slightly slower or that part of the run was shaded, it seemed to help and the run was more manageable in the heat than run 1.
So if you need an excuse for an ice-cream perhaps you can just say you are "pre-cooling" ready for your next run...