I live in Queensland too.
All the animals in Australia have to adapt to extremes. Usually it is really hot, and most winter days are pleasantly warm, and we are forever battling drought, but every few years we have an extreme cold patch. Like now, for the last month we've averaged 5 degrees Celcius a day. In some places it's reached -5 degrees and snowed! It never snows! But it's getting warmer and soon we'll be reaching 30 degrees again.
All the guinea pigs born in Australia have a bloodline of pigs that have adapted to Australia. And there are very few longhaired guinea pigs (besides abyssinians) in Australia.
When its hot I fill a shallow container half-full with water and put a handtowel inside the hutch. The handtowel soaks up the water and the pigs have fun rolling around on it. When its cold I just put a few handtowels in. It's really easy for them to adjust to the temperature if you provide them properly.
ermm ..exscuze me suzy_99 i am from the uk and i have both my little pigs living indoors in a C&C cage ....and most of my friends do to! so don't start blabbing about things when you don't really no for sure......oh nice cage by the way!!!