In the middle of Johannesburg, South Africa, the tallest residential building in the southern hemisphere has a reputation as hotbed of crime, drugs and prostitution. But things weren't always this way.
When you hold an object, like a book and a metal iPhone, which feels colder? You'd probably say the metal or glass object every time, over a warm book. The problem is, the difference in temperature isn't really what you're feeling.
This video from ABC in Australia explains the principle of thermal conductivity to people on the street. via Catalyst