It won’t stay cold through a shift. Things warm up fast out there.
In Iraq we’d take water bottles and put them in the freezer the night before. They’d last most of the day, drinking the water from each as it melted.
That was in Humvees w/ no a/c. If these men were walking in that heat that’s unforgivable. At 51 there’s no way his body respiration can keep up in that heat.