the heat will cook you. no joke.
you really have to be prepared for it.
that being said i have dry washed moristown, little san domingo, rich hill at night in the summer.
it was not too bad. i would not do it in the day time.
you do have to drink at least a gallon or more of water every 3 to 5 hours to stay hydrated.
the harder you work the more water you need.
i will not go out mining without at least 5 gallons any time of year.
when the suns up, a long sleeve cotton shirt and a wide brim hat are a good idea.
November to May would be better. its cooler and less rattlers.
if you head up north its only about 90 degrees or so in Prescott this time of year.
lynx creek has some nice gold if you can hike a bit and dig to bedrock
dredging season, there's not much water in Arizona.
i have done some dredging in az and have found i like detecting and dry washing much better. being bent over all day dredging is hell on your back.