Aspergillus calidoustus is a species of fungus in the section Ustus, which grows at 37 ðC (formerly called A. ustus, a species that fails to grow at 37 ðC) and exhibits high minimal inhibitory concentrations to azoles. It is considered an agent of opportunistic infection.
Colonies can appear white and progress to brownish-yellow. Curved conidiophores and Hülle cells can be identified. The conidia are echinulated (spiny).