I imagine that since dogs can only cool down with their tongues unless they go in water, that maybe all the fluff keeps them insulated from the heat a bit? Obvs they will be warm, but that layer of trapped air next to their skin will stay at the same temperature all year round pretty much I think.
"Let me tell you, when yung Rouj had his Senna and Mansell Scalextric, Frank was the goddamn Professor X of F1."
Sorry, worded my post badly, what I meant was that although furry dogs (and as pop said, all dogs) need to be careful in the heat, big wooly dogs don't cook themselves in the way you might imagine in hot climates, I was just speculating that it could be because the same thing that insulates from the cold, also insulates them from direct heat from the sun and hot air - getting hot anyway from running around or just existing in that climate notwithstanding.
Bit like Jones, he's super duper wooly even in summer after he's shed his winter coat, but really he only needs special care on the hottest of hot days and that's usually a combo of draping him with a cold damp tea towel for a bit or plonking him in front of his water bowl and trying to encourage him to take a couple of sips (also I mix a bit of extra water in with his wet food when it's hot just to get some extra liquid into him).
"Let me tell you, when yung Rouj had his Senna and Mansell Scalextric, Frank was the goddamn Professor X of F1."