How do you avoid searing yourself from the saddle?

I don't take any measures, but when I lived in AZ, I put a towel over the steering wheel of my car so that I could touch it without experiencing 3rd degree burns when I got ready to go. Perhaps a hand towel and a velcro strap would work on a bike's saddle.

Oh, and if you've a QR seatpost clamp, you could always take it in with you.

Wear pants.

OUCH!

other options:

give it a little squirt from your water bottle to cool it off.
or get a suede saddle. They don't feel as hot after having sun beating down on 'em.

Don't use those two in conjunction, however.

Keep your butt on the saddle, except when your bike is in the shade.

Get a white saddle?

Having lived & cycled in AZ since 1986, I've not experienced that problem. EVER.

I've been riding bikes in southern Arizona since 1967 and not had that problem either. But I'm open to the idea that people have different butt sensitivity.

my guess is leather and synthetic leathers saddles are the ones that get hot. the lycra fabric type covered ones probably dont

Park it in the shade. or put a towel on it.