Hinkemeyer Yeah, sunglasses and a leather jacket would do the trick. Ironically, this is where I got my start with Siberian Huskies. My original three dogs had to survive record-breaking 122 degree temperatures in July, when even the airport was closed. While Minnesota summers are cold in comparison, Siberians can still suffer and must stay cool. Note that at the beginning I mentioned heat and sun, not temperature and sun.
Heat is the combination of the temperature and humidity.
The best piece of advice is to just use common sense. If you are uncomfortable outside, your dog is probably very uncomfortable. The primary reason, of course, is that lovely Siberian coat. As you probably already know, dogs do not perspire. They cool themselves by panting - losing their excess body heat from their mouths.