Wilting courgettes and squashes

My courgettes and squashes are in my front garden, which is baking hot, full sun from mid morning to evening.  I'm watering copiously every evening, but the leaves still wilt quite badly during the day. They always perk up again when the temperature drops, but I worry that it will affect the plants long term. The squashes in particular have already suffered from the cold, dry June, and had only just started to get going when the hot dry weather began.  Is it worth trying to provide some shade, eg rigging up some sort of tent, or would this do more harm than good?

For these I sink 2 litres plastic bottles with the bottoms cut off & the lids removed next to each plant & water into those usually 1 bottle per plant, I also do the same for climbing beans. You could also add more than 1 if it’s extremely hot. It really is amazing how much the plants thrive if you can get the water down to the roots. I’d also add a thick mulch around the plants to insulate them from the heat.