We are laying out reflective insulation over the beds. This is the stuff we use on the inside roof  of the chicken houses to keep them warm in the winter and cool in the summer.
Why on the beds? We are still sowing lettuce, greens, spinach etc and they do not like to germinate when it is hot. So imagine you are a seed in one of these beds and the sun is beating down above you on a 100 F day. You would not be in a hurry to germinate, I suspect. The insulation is there to keep the beds cool for those critical 72 hours after the seed is sown and irrigated.
Did it work? Firstly you have to take into account that we do some crazy things and some of them do work. Most of the time the kind of work and  we have to refine the experiment. That said... the wind blew all but one of the sheets onto the summer squash. But...The bed where the sheet stayed on did have leggy spinach under it. meaning that the sheet had encouraged germination and we need to remove it after  three days not six. Where there was not sheet the spinach germinated very erratically.
Now we have to figure  out a way to keep the sheet in place and make sure we take it of in time.