Two gun crews are doing daily chores but one is not in a hurry. Heat and humidity were 24 hour a day companions. I doubt our temperature was ever below 75 degrees and exceeded 100 many days; Tay Ninh was a greenhouse. Not wearing a shirt was a major violation of Army regulations, but even in the early morning most men removed them. Mosquitoes were the main reason to keep your shirt on.
Vietnam had a limitless supply of insects and many of them bit, sucked or stung. For 5 days we were invaded by clouds of some unidentified critter the size of a grasshopper, shaped like a cockroach. They grabbed with their feet and hung on with a death grip. We never saw them again or ever identified them.