[78-L] Can vinyl be unwarped?

[Robert M. Bratcher Jr.]

I realize this is not for a 78 rpm disc (it's a Kim Clement gospel LP 
from 1983) however the record is badly dished so that I can't play it 
well on the outer track of the first side. My question is can a vinyl 
LP be safely returned to flatness in a household kitchen oven between 
2 sheets of glass? If so then how can it be done safely? What 
temperature should I use? Where would I get the glass to put the 
record between? Or is there a better way to unwarp a record? I'm open 
to any ideas.....