Comment by wildzzz
Immediately take them out of the oven and store in the smallest airtight container you have. Obviously they'll absorb the humidity in the container and whatever is introduced anytime you open it. Ideally, keep them in containers that have an excellent seal and minimal internal volume like quality ESD bags.
I don't think I've ever seen an antistatic bag with a very good seal, and I'm not sure it's a good idea to drop something directly out of a hot oven into them either.