The third base side of the field is the sunny side. So to ensure shade and lower temps, you will want to be covered from the overhang.
Behind the visitor dugout are smaller sections 118, 119 and 120. These sections, along with surrounding sections, are covered and will give you the best chance at beating the heat. Additionally, you will only be a few steps from the concourse, limiting your walk to grab water and go to the restroom.