As you know it gets pretty hot here in the summer too, and my dogs have always done ok. Of course they can come inside to cool off with air conditioning, always have fresh water, etc. I take them hiking in the summer often and I've never had a problem. Keva is not as tolerant of the heat as Nebo, I think it is her darker coloring, sometimes if she gets too hot she'll sit and refuse to continue (she's never done it on a hike though, just walks). I have a kiddie pool on my deck that I fill with water in the summer, and they love that.

I would say as long as your brother intends to allow the dog indoors with A/C he should be ok. If he's going to hike with the dog it would need to be on a cooler day, and he needs to make sure to bring lots of water. Many people think they should shave huskies because of the heat...tell him that he would just need to brush the dog regularly so there isn't a build-up of undercoat, shaving is not a good idea. If he isn't already aware, he should know that huskies are generally not good off-leash so it will need to be leashed hikes.

Personally I think that huskies do prefer to live in cooler climates...my dogs LOVE the snow and I know they'd miss it if I moved where it didn't snow. But if there's huskies that need to be adopted in Phoenix they're going to live in that heat anyway, reguardless of who adopts them. Just make sure he's prepared for the challenges of a husky (here's just a few of their fun traits http://www.essortment.com/all/siberianhuskyr_rydp.htm ), I wish him good luck in finding the perfect dog for him.