However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing, kidney problems (such as change in the amount of urine). This is not a complete list of possible side effects.
They are more active when it is cooler, but they can and do come out of hiding at any time of the day. Here in the desert, Arizona Rattlesnakes can easily overheat and die if they cannot find a cool place to keep themselves cool.
Arizona recognizes all states permits. If you go to an AZ DPS location and have a permit from your state, they may issue an AZ permit on the spot. Someone I work with, temporarily here from Texas, did that. AZ is a Shall Issue state but you do not need a CCW to carry concealed in AZ.