240 rule

Twice yesterday I applied the rule of 240 for the first time. The dough seemed "better" somehow and 'm really not sure how, but this is something I think I'll keep doing. My house is on the cool side and I was using water tiemps of 104 and 106F. Those temperatures make me very nervous about killing the yeast. Is there any problem with heating the flour a few degrees in a warm oven? I would think this would work as long as the flour isn't scorched.

Larry