just soak the piece of pex in super hot water, you can even boil it and it will become like a limp noodle..
no effect whatsoever, after you have the pex on the fittings you can wait a few minutes till it cools down and then crimp...there are temp ratings printed on the pex tubing..Does it affect strength at all? Any issue using the Uponor PEX expansion tool with them hot?