quick question about frog mats

[EZ Smoker]

The missus is making calzone in a 500 degree oven.   I bought some frogmats from yard and pool, so I'm wondering if I can use them for this.  Is 500 degrees too hot.  I just read the write-up on frogmats at the yard and pool site, and it says they can go up to 550 degrees, but I thought I'd check to see if anybody has any experience with this.

[FLBentRider]

I've used them in the heat, I'm not sure I've done 550F, but how hot is the broiler anyway?