There were times during the night when all the jungle sounds would stop at once. There was no dwindling down or fading away; it was all gone in a single instant as though some signal had been transmitted out to all life: bats, snakes, monkeys, insects, picking up on a frequency that a thousand years in the jungle might condition you to receive. But, leaving you as it was to wonder what you weren't hearing now, straining for any sound, one piece of information. The thought that there were hundreds and thousands of NVA and VC out there just to do you harm. The thought that you could turn any sudden silence into a space that you'd fill with everything you thought was quiet in you; it could even put you on the approach to clairvoyance. You thought you heard impossible things: damp roots breathing, fruit sweating, fervid bug action, the heart beat of tiny animals. You could sustain that sensitivity for a long time, either until the babbling and chittering and shrieking of the jungle had started up again, or until something familiar brought you out of it, a chopper flying around above the canopy or the strangely reassuring sound next to you of one going into the chamber.
Sometimes you'd get so tired that you'd forget where you were and sleep the way you hadn't slept since you were a child. I knew a lot of people that never got up from that kind of sleep; some called them lucky (Never knew what hit him), some called it F*(&#$ (If he'd been on the stick....), but that was worse than academic; everyone's death got talked about. It was a way of constantly touching and turning the odds, and real sleep was a premium. I knew a guy at Kontum who could go to sleep just like that, say, "guess I'll get some", close his eyes and be there, day or night, sitting or lying down, sleeping through some things but not others; a loud radio or a one-five-five firing off in the distance wouldn't wake him, but a rustle in the bushes fifty feet away would. Mostly at night what you had was on the agitated side of a half-sleep.
You thought you were sleeping but you were really just waiting. Nights there were harsh functioning of consciousness, drifting in and out of your head, looking up through the trees at the glimmering night sky of a combat zone. One night I woke up and heard the sounds of a fire fight going on several clicks from us. We knew it was one of our patrols but we were too far away to help. All we could do was listen to the gunfire and the call for help on the radio. Muffled by distance it sounded like noises we made playing war games as children; it enriched the game and this was the same.
Only way out of hand at least, too rich for all but a few serious players.
Night Sweat is instant involuntary weight control.