Of course!

I don’t see a problem with it. My kids are 4 and 6 and I’m currently 22 weeks pregnant, also living in far north qld with no aircons as the moment. I walk around most days in just underwear and a crop singlet with no bra. Its so much more comfortable and the kids don’t care. They mostly walk around in just jocks or shorts when we are at home anyway.

In some overseas countries parents and kids for that matter walk around naked naturally. In Scandinavia they don't have our hang ups either. My husband walked around the house naked when he got out of the shower or first out of bed and would walk into the kitchen naked even when our daugher was a teenager. His argument was the human body is natural and normal. In fact HE thought it was odd that I felt it was something that we should be ashamed of and cover up as if it doesn't exist... I eventually came around to his way of thinking. Now my grown up daughter also wanders around naked, very comfortably and happy with herself and with others and has absolutely none of our western hang ups. So, go naked I say! It is natural and your 3 year old is going to discover it one day anyway - let them grow up also thinking the body is natural and nothing to be ashamed of.