Yeah, the glass on that looks very thin, so it would make sense if got too hot. As far as screens go, I've never used one in my many years of smoking. Many smokers do what is called a "plug nug" which is basically a piece of bud bigger than the hole in the bottom of the bowl. You put it there to keep the smaller bits from going through as you inhale, and when the bowl is done, it'll pull through- be careful! It can get into your mouth and taste like shit.

Bowls get most people moderately to very high. Bongs tend to give bigger more voluminous hits at one time, so they can really get you wrecked. Eating brownies is also a very strong, long-lasting stone. Joints are pretty nice, too.