With regards to the Gold Coast, with due respect, I think Nick's comments overstate what you'll experience. August is close to their winter, while warm for southerners, it is quite mild there - mid 20s generally with some days higher 20s from my experience over the years. Humidity levels are also relatively mild, and nothing like Asia until a few months later. Airconditioning is hardly necessary. But the same rules apply, lots of gel packs and some care if there is a big difference between indoor and outdoor temperatures. BUT remember it is not just high humidity to be careful with, it's the sudden large change in temp that must be managed. You should have no problem whatsoever in August up there. By the way remember in some climates cold winters can pose similar issues of humidity (moisture in the air) and sudden large temp changes.
With regard to UV rays and sunlight, I understand there are differing UVs, but a lens technician here told me it is worth doing if you have lenses that get stored for long periods and if you suspect lenses have been exposed to moisture. The UV globe in a box is the most effective remedy but be careful not to do it to excess as rubber seals are adversely affected by long exposure to UV.
