SlowJoe

It's a chinese/asian culture thing to drink hot water and believe drinking cold water isn't good for you. I don't know the exact origin of the belief but it could be a holdover belief from when they had to boil all their drinking water to avoid getting sick. Also, the chinese had a relatively late start into the industrial revolution with most of the population living outside major urban areas still having poor to no modern infrastructure to this day.

I think they mean to say the younger the parents are when the children are born.

I have a feeling the author might have converted from imperial to metric. .357 magnum is the same bullet diameter as 9mm parabellum and .38 special. I could be wrong, though, and the author just chose the incorrect cartridge.