How do you tell if a tank is tempered?

[Doormatt]

Hey everyone!

I've got (what I'm 95% sure is a) 37G tank. When I was talking to one of the guys at Ocean Aquatics, he said that he's rarely seen a tempered 37G tank. Now that I do a few searches, I see that all the charts list 37G tanks as being tempered. How do I know if my tank IS tempered, and if so, is there any way of telling if it's just the bottom pane?

Thanks!