does anybody stick their seed starting pots / other garden paraphenalia in
a minigreenhouse or cold frame during the summer to sterilize them?

Is it a dumb idea, waste of time or what? As it is, I don't bother
washing, but if I'm going to have a cold frame, i would if it might be
useful outside of winter anybody know what temperature plastics will start
melting at? Cold frame will have real glass.