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.
Keeping your immune system up in the winter months is always a good idea, especially since Arizona has the highest number of flu outbreaks each year. Stay protected with a healthy diet and exercise, and you may also want to consider immune booster injections for the season ahead.