As a result of this thread, I bought a max/min thermometer.
One thing this told me was that over the recent sunny weather of late April, my greenhouse in Bristol has been reaching 30-34 deg C during the day(if the thermometer is to be believed).
I have put a whiting layer on the glass to reduce the impact of the sun, but was still getting these max temperature until it cooled late this week. I shudder to think what it was last summer during the extended hot period.

Any advice on temperatures this high & plants to watch out for (this year I'm looking to have tomatoes, peppers, aubergines & okra in there).
Colin