I'm awful cold natured, so I keep a space heater close to me. I've learned to not leave my e-cigs in front of it. When it happens, my clearo's gurgle and leak until I unscrew it from the battery, and blow it out. The battery will be nearly flooded. Of course, the battery gets hot as fire, too.
One side of my laptop has an exhaust fan pushing heat out. I can't leave my e-cigs there, either. A few times I put my ecigs above my keyboard, in the crease below the monitor. It's warm, but not "hot" by my standards. If I leave them there too long(a few hours), they will gurgle and leak.
I don't know where the line is, but heat will definitely affect a clearo. Is there a difference in humidity between Australia and Arizona? I live in the southeast, and summer temps regularly hit 95-100, but with 60+% humidity. "They" say Arizona doesn't feel as hot b/c there's no humidity. I've seen 2 weeks straight of 100+ temps in humid-less Denver. "They" are liars.