My ~9 mo. old male Veiled cham's left nostril has become crusted over with a white, salt crystal-like substance. He has been spending all of his time in his scrren cage outside on my patio for the last few months (Midwest). Last couple of nights dropped to the low 60s and I didn't bring him inside or provide heat lamp. Otherwise healthy looking, although displaying threat/stress colors late at night and while sleeping, which he hasn't done before. PLEASE HELP!