Hi,
Can you get us some close up clear pics of the scales?
What kind of substrate are you using and what kind of heat - if it is a UTH is it on a thermostat?
It looks as though it could be scale rot but it is covering an awful lot of area to spring up quickly.
The vet is definately the good idea with anything that widespread and I hope it is something easily treated.
I think the best plan until the vet appointment would be changing the substrate to paper towels and keeping everything as clean as you can.
Anyone with better eyesight get more definate info from the photo?
dr del