If you didn’t know otherwise, you might think Box Hill was abandoned. Not a single person was sighted in the north-west Sydney suburb on Saturday afternoon, the faces of real estate agents on billboards the only sign of human life.

The decision of residents to stay indoors was entirely reasonable. It felt like 55.2 degrees.

The air temperature at 3.37pm was 42.8 degrees, according to our measurements. But that metric doesn’t account for the wind, sun, humidity and other factors that affect how the human body processes heat. The more representative metric, the globe temperature, or “feels like”, painted a picture of a new suburb halfway to boiling point.

An infrared thermal image of Stargazing Park, Box Hill. The softfall was the hottest, with one point measuring 87 degrees.Credit: Max Mason-Hubers

So as Sydney sweltered through its hottest January day in six years, the Herald took two specialist weather measuring devices around the city’s west and north-west to see just how hot it felt. A heat stress tracker recorded the weather, and a thermal imaging camera revealed the heat on........

© The Sydney Morning Herald