This is what I've been doing,
the netting is doubled on top, and I add another layer for the midday sun. 39 degrees yesterday! At night I pop a sheet of wood on top in case it rains.
I tried just a few to start with. Seeds sown on the 18th April, seems to be working so I added the top right tray on the 23rd, hoping to see some hooks there soon.
Good luck All, Ezzer.