Male Veiled w/ "Crusty" Nostril

[NDeuser]

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!

 

[Parandrus]

Chameleons can excrete salt through their nostrils much like iguanas and other lizards do. With a wet Q-tip you can remove the excess buildup and see if it happens again or how soon. Make sure he has plenty of water to drink and that he continues to act good. I wouldn't think much of it unless you see other changes.
Veileds should be able to tolerate cool temperatures even in the mid 50's as long as they can warm themselves up again the following day to their preferred temps (hot).

Ivan