Those who have suffered under this heat wave with their Prii, how many months/years of life would you suspect this deadly summer has subtracted from the battery? It has me a little concerned, as I didn't have an air conditioned space for it as temps hit around 110 and stayed in the triple digits for the majority of the summer. Not to mention, just recently I read a letter sent to a DMN editor about someone whose 2005 Prius battery failed recently at 110k miles (outside of warranty and perhaps precipitated by this heat) and of course the dealer cost was $3500, so they were asking for alternatives (used from junk yards/impounds being the obvious answer). I guess the Phoenix owners might have some experience/insight on this, since they usually experience the hottest summers in the CONUS.
From the anecdotal reports here on Priuschat, it seems that there might be a correlation between HV battery failure and high temps along commutes that involve big elevation changes, in theory cycling the battery more between between low and high SOC. If you're concerned about heat, I'd try keep the car cooler by finding covered or shady parking or just a spot where it happens to be in sunlight for fewer hours of the day. I'd also use a sunshade and maybe keep the windows opened a crack.
Good observations and recommends...it is likely too late this summer. Time will tell how it holds up. The only benefit in our case is the elevation changes relatively little here and in my case in particular, it didn't undergo a commute (it baked in a parking lot instead), except on the weekends.
