If you were to take a #thermometer out into deep space and leave it there, far from any source of radiation, it would read 2.73 Kelvin—a little lower than minus 454 degrees Fahrenheit. That happens to be the coldest naturally-occurring #temperature in the universe.
Space is kept above absolute zero by background radiation left over from the Big Bang. Although space is nevertheless very cold, it’s interesting to note that one of the biggest problems encountered by astronauts is actually heat. Bare metal on orbiting objects can reach five hundred degrees Fahrenheit (260 C) due to the unimpeded heat of the sun, and needs to be covered in special coatings to lower the touch temperature to “only” 250 Fahrenheit (120C).

Outer space itself, however, is constantly getting cooler. Theory has long predicted this, and recent measurements have confirmed that the universe is cooling by around one degree every three billion years.