@Alice
A thick piece of wood does the job. That is the cheaper variant of a spacecraft heat shield, an ablative heat shield made from fiber glass in resin. Woud will burn at high temperatures but it doesn't melt. The outer layer will burn away milimeter by milimeter exposing a new fresh layer. As long as your piece of wood is thick enough, something like 50 mm, you will have enough time.

@Alice Asbestos-coated, lead-lined, ceramics. I can hook you up with a guy who knows a guy who might be able to help, once he gets out of prison.

@Alice what about clay
they're doing wild things with clay. its this new stuff

@Alice

The Apollo heat shield?

(I don't trust these new fangled spacers, and the space shuttle had deadly engineering problems)

@Alice This is why asbestos exists.

@Alice Beryllium absorbs a bunch of heat is strong doesn't rust comes in all sorts of alloys. It won't melt in lava. You'll die machining it. It's kinda perfect!

They used to use beryllium heat sinks to protect the radios in cars when baking the paint on.

I'd suggest space tiles from the shuttles but you need vacuum to make them work well and that's hard to manage in our environment.

@Alice

. . . is this a gift for your crush?

@Alice this sounds like a job for Russian Trump asbestos.

@Alice
Make it out of cushions ... always works when the floor is lava.

@Alice

Diamonds..... diamonds might work..🤔

@Alice What do you have against a bottle of propane, a rubber hose, a plastic bag, and some duct tape?

@Alice borosilicate glass