The only time this clay gives off a smell is if you try to cure it at a high temperature.

The Primo brand is especially hard after curing. Any of the polymer clays can be reheated, either to add a fresh piece to the hard piece (no adhesive needed) or to harden a piece that wasn't quite done. 5-20 minutes, depending on thickness is usually sufficient, but reheating will only make it harder, not damage it.

This is a strong material, not brittle/breakable like stoneware or porcelain clays. It can be broken when rolled thin (like these Exacto blade handles), but they're just handles, not prybars. But even this thin, it does take some effort.

I don't know of anything that would be better for these conditions, even on-site if you had some heat. Polymers start curing at 90F, so I suspect that if you took a package with you (usually 2"x2"x5/8"), formed it, & set it near a heat source or improvised a small solar oven, you could come up with something. The curing temps for these clays vary by brand, but mostly between 165F & 265F.

If you put it in a fire, it would probably burn like any plastic.