Pretty much agree with all this in the cold environments that would be off coast where I have 'logged in' approx 6000 winner SAW hours. The wood is likely just really tough up that way. pretty much you are only going to b-chair if you left to much hinge and you hit with your next row. That's usually Just Pine. Not the Aspen, Birch or Cottonwood...they are bullet proof. Prehaps because they do break off easier? BC Fallers speaks of this and it may be true. (Although I have fell everywhere and in all seasons in BC) Now if you Fell cottonwoods all winter in Central BC and went to the coast the next day to fall the same species of cotton wood that is not frozen wood then you may get killed that day from a chair. Yeah that should be in the book more importantly. BUT it's NOT. Along with anything about falling on the west coast. Books a guide line. Big difference between -20c and -40 c Just like metal, after -35+ things snap. ------------ Right! Trees are endothermic 'Heated from the sun' A heat energy from without.