Where: Area 05 (front yard).
When: Last night, 02:00 to 03:45.
Conditions: High of 46* F, dropping to a low of 44* F, light and variable wind (< 5 mph), no humidity to speak of.
Top Insulation: Poncho liner made into a top quilt by tying foot-end ties together as well as mid-point ties to make a footbox.
Clothing: Nike DriFit polyester t-shirt, nylon/spandex compression shorts underwear, nylon/spandex running shorts, thick acrylic sleeping socks, poly/cotton baseball-style hat.
Result: Unsatisfactory; I was cold.

I slept cold last night for a couple of hours, testing out the limits on my Garlington insulator. I suspend a poncho underneath my DIY hammock using Velcro and stuff a crumpled space blanket into the resulting airspace. I show it off at about 8:35 in this video:



The temperature when I went to bed was 46* F, according to my new AcuRite thermometer that I picked up at WallyWorld. I was well-fed (an individual-sized pizza at work and a pair of Reece's Peanut Butter Cups right before bed), sober, and hydrated (0.5 L an half-hour before bed).

I was cooler than I like on my back, but not cold enough to keep me from sleeping. I fell asleep fairly easily, despite the normal night noises of my neighborhood.

About two hours later (03:44 by my watch), I woke cold. Uncomfortably cold, to the point where I could tell that I wasn't going to be able to get back to sleep.

Rising, I checked the thermometer, seeing that it said 44* F. I hadn't realized that two degrees would make that much difference, but...

I now know that, for me, my Garlington lash-up is good to about 45* F. Below that, and it won't be sleepable. My comfort level with it is about 50*; I already knew that from field testing. However, I was wondering where my hard limit for the night with it would be, and that appears to be 45* F.

It's always worth testing your gear before you go out!