How big is the enclosure?
One heat pad should be fine if the enclosure is properly sized. However, what are you using to regulate the heat pad? If nothing, then you HAVE GOT to get some sort of thermostat to keep the temperature down. UTHs get far too hot for snakes unregulated.
That's just a little stuck shed. You can soak him in some tepid-warm water for about 30 minutes and see if they'll peel off if you rub them lightly.

I don't recommend temperature or humidity gauges.. get thermometers or a hygrometer that are digital and the thermometers should have probes on them.

Also, the cereal box is fine for a temporary hide, but it will quickly get dirty and musty and possibly collect mold. I recommend getting something more permanent. http://www.reptilebasics.com/Hide-Boxes-p-1-c-282.html