It depends on what variety you are growing. I think arugula will bolt a lot sooner than lettuce and a few days of 80s weather isn't a big problem as long as your lettuce is watered thoroughly.

Its been those temps for a while and predicted to stay that way for at least the 10 day. The varieties are little ceasar sylvestra speckles four seasons buttercrunch black seeded simpson red lollo and some space spinach.

The lettuces you list, and the spinach, are all varieties well suited to cut-and-come-again harvesting. You should take a few of the largest leaves from each plant every 3 or 4 days. Once they start to show signs of bolting, cut the entire plant and reseed with something else for the summer. You can re-plant things like arugula and spinach all summer but you will probably only get one harvest before they start to bolt again, so you are better off planting warm-season varieties and waiting till fall to re-plant those crops. If you have anything to transplant, and are using wide rows, you can put taller plants on the south side of the salad plants, which will shade them. This will make them grow slower, but it will help to keep the soil cooler and they will last a little longer. You can also experiment with shade cloths, light colored mulch like dried grass clippings or straw, or misting/evaporation, but nothing you do is going to change what the sun is doing, so you have to accept that things will bolt eventually, no matter what.