extreme heat garage issues

https://wool-wiki.win/index.php/Power_Outage_Garage_Access:_How_to_Get_In_and_Out_When_the_Grid_Goes_Down

Our garage turns into an oven when the heat hits triple digits, making it nearly impossible to work out there for more than a few minutes. Tools are too hot to touch, and I worry about the car battery and any stored items like paint or glue getting ruined. We're looking into better insulation or a portable AC unit just to keep the space usable.