I lived a year in Tucson back in '94-95.... it was 106+ the day we arrived and were unloading our truck... locals thought we were crazy working in the heat... then when Dec/Jan arrived we were still running around in shorts and t-shirts... again locals thought we were crazy.. they all had their jackets & sweatshirts on... temps were in low 70's and high 60's.... after 15 years in Houston at 98+ humidity, the dry temps felt good.... they all said we would acclimate but didn't stay long enough.