WordNet sense 1 (dried out by heat or excessive exposure to sunlight):

parched, adust, scorched, sunbaked

WordNet sense 2 (free from liquid or moisture; lacking natural or normal moisture or depleted of water; or no longer wet):

dry

WordNet sense 3 (hardened by subjecting to intense heat):

burnt, burned

WordNet sense 4 (made hard or flexible or resilient especially by heat treatment):

tempered, hardened, toughened, treated

WordNet sense 5 (having been prepared for eating by the application of heat):

cooked