When it was bad was during my early October trip. For some reason being too cold (I didn't have enough insulation under me) made the bladder thing much worse. I would just begin to warm up when I had to go outside again. It was well after midnight before I got to sleep! The moon and stars were really beautiful but it was hard to appreciate them at 18* and with no sleep! Interestingly, I didn't start shivering again until I got back in bed (and then only on the ground side).