Hi,
A Phoenix vandweller here, though I try to escape the summer heat, it doesn't always work.
I park in the shade of commercial buildings whenever possible, and try to find green areas so the cooling effects of the grass and trees can help. It does lower temps.
Yes, you need some tinting though that's spendy when on a very tight budget, so use car sunshades until you can afford to tint it. Make sure you leave the driver and passenger front lighter than the back, tint shops know the laws.
Please don't leave windows down for a breeze, your safety is more important. The 12 volt fan blowing on you is smarter. I use a fan and just deal with the discomfort.
You are able to go up Mt Lemmon, as others have said, to escape some of the heat. That would be for daytime obviously, and when not working.
The City of Tucson has parking codes, here's the list but my IPad wouldn't open the links... Section 20-254 may be what you need to read.
Division 5. Nuisance Parking Controls
Sec. 20-246. Penalty.
Sec. 20-247. Parking for certain purposes prohibited.
Sec. 20-248. Parking regulations for peddlers.
Sec. 20-248.1. Parking regulations for peddlers in certain central business district streets.
Sec. 20-249. Freight curb loading zones; location of provisional zones in parking meter zones.
Sec. 20-249.1. Same—When nonauthorized vehicles prohibited in provisional zones.
Sec. 20-250. Parking on property of another prohibited without permission.
Sec. 20-251. Parking in parks and playgrounds.
Sec. 20-252. Parking on city-owned property.
Sec. 20-253. Parking for purposes of sale on unpaved lots.
Sec. 20-254. Parking prohibited during certain hours on certain streets.
Sec. 20-255. Residential permit parking.
Sec. 20-257. Special events permit parking.
Sec. 20-258. Additional permit parking programs; fees; director of transportation authorized to establish additional permit parking programs and to establish annual parking permit fee.
Sec. 20-259. Expired registration.
Sec. 20-260. Stopping, standing, parking prohibited between the curb and sidewalk or in an unimproved pedestrian area impeding continuous pedestrian use.
Sec. 20-261. Unattended and inoperable vehicles prohibited.
Sec. 20-262. Truck parking on streets not designated as truck routes prohibited.
Sec. 20-263. Recreational vehicles; commercial vehicles.
Secs. 20-264—20-270. Reserved.