Having grown up in Texas, I feel a little nostalgic when the days get unbearable. I enjoy relaxing during the heat of the day. Hot days in the garden require a little planning. First off, get up early to get things done before 9:30/10am. Most importantly, drink water and keep in the shade when possible. Wear a hat if you have to be in the sun. Soak yourself with the garden hose if you get overheated, why not?
Now, for the plants. Hot days require a little early morning work. Make sure you water deeply in the early morning. Harvest any of your ripe tomatoes, strawberries, herbs, or greens that you may want to eat early in the day. If you see containers wilting in the afternoon sun, water them at the base of the plant to not burn the leaves.
Take some time in the evening to enjoy the cooler air outside. Often this is the time when I see hummingbird moths! I have added some solar powered lights to the garden that really make the night enjoyable. Have a cool drink and relax.