“It’s cold out”. That’s surely one of the most common salutations you’ll hear from someone stepping inside from outside on a day that the temperature hovers around 30 degrees Fahrenheit (or lower!).
Surely, you feel cold when the temperature is that low. But what is this “it” that is cold?
Yet most everyone agrees with you when you say that on a cold day.
What really happens when you say, “it is cold out” rather than saying, “I feel cold”? While saying “I feel cold” is certainly more accurate, we may not feel comfortable phrasing it that way. On the other hand, saying “I feel cold” makes you responsible for how you feel. whereas saying “it is cold” puts the focus on the outside environment.
Everyone may agree with you when you say, “it is cold out”, but phrasing it that way leaves out many creatures who might disagree. Think about a polar bear marching about in 30-degree Fahrenheit weather. To the bear, 30 degrees Fahrenheit is probably balmy, and may be downright uncomfortable. The bear’s probably saying “wow, it’s warm out.” For the bear, the statement “ ‘it’ is warm” is true, but you may disagree!
What about single celled creatures that don’t have the capacity to feel warmth? Is ‘it’ warm for them on a 70-degree Fahrenheit day? Single celled creatures may thrive at that temperature, and they’ll start dying off when the temperature of their environment gets too hot. A more accurate phrase is “it’s too hot for the single celled critters to live”. Most people will understand you mean “the environmental temperature is too hot for the single celled critters to live”
While colloquialisms such as “it is cold” or “it is hot” is convenient, using them leaves out some important information. The missing information is the fact that you are part of the environment and that ‘it’ describes the environment (albeit silently and implicitly).
Would the statement “it be cold out” make sense if you weren’t there to feel it (or measure it in some way)? Saying "it is cold on Pluto" requires imagination. We are inferring that we would feel cold on Pluto- without experiencing that condition.