Yesterday in Montreal, it was -35 celcius (or -30 Fahrenheit). There was a dead decaying limb on a Crimson King Norway maple that needed removing and since the hydraulics on the bucket truck kept freezing, I decided to climb it. I've never climbed at these temperatures before and didn't think it posed any danger, just a little uncomfortable with the freezing winds. However, as I took the limb down in pieces and gradually moved down on my friction hitch (v.t. tied with 10mm ocean on a 1/2" 16 strand), it would jam every few feet. I would really have to work at it to get it to keep moving and when it did come free, it would slide alarmingly quickly for a second before acting normally again. I inspected the rope and prussik before going up and there weren't any abnormalities, bulges, glazed spots etc... When I got down I checked the rope again and found that in a few spots, the rope was frozen. The only thing I can think of is that as the friction hitch arrived at these frozen sections, the rope couldn't pass through the hitch normally because of the rigidity of the frozen section...then as i worked it through, it would force the hitch open ever so slightly so that when it passed the frozen section, it would slide quickly, seeing as the hitch had been opened slightly, before biting normally on the rope. Any thoughts?? I don't know if anyone has any experience climbing in such temperatures. Yesterday was definitely a first for me!