I've been usign the ND-5 handheld for a few months now and it does get low or completely cut off at about 30-40 degrees. I keep a cord on it that I wrap around my wrist so that I don't drop it and when I'm not scanning with it, I hang it around my neck and keep it inside my coat, up against my body. This keeps it very warm and has stopped the failure due to the cold temps. If I use my binoculars while using the light I can tell exactly what I'm looking even past 200-250 yards. Hard for me to take a shot at that distance holding the light and rifle at the same time though without something to brace against.