On very cold days, someone can say that it's freezing outside. On very hot days of summer, can someone use cooking or any antonym of freezing, if one exists?
It's both a British and US colloquialism to use 'boiling'.
Also referenced here: http://www.thefreedictionary.com/boiling
I've also heard scorching used; it seems to describe the condition of the pavement quite well.
While 'boiling' is a commonly used option, my suggestion would be 'sweltering', as it removes any possible ambiguity.
As no-one else has addressed this specific point: Cooking is used in this sense in Australia at least.
Cooking seems to capture the feel of being in an oven in such conditions. I personally would probably only use it in temperatures well above blood heat.
With regards to the other words suggested:
Boiling and scorching are common in the UK. I vaguely recall a tabloid headline 'What a scorcher'.
It seems to me that boiling is hyperbole, as others have noted.
Scorching is however literally true, just like freezing can be.
Freezing is also used in the UK and especially Australia in a non-literal sense.
Torrid is of course also correct provided it is a dry heat. I don't hear spoken much (anyone differ?), but it is definitely written use.
Sweltering is valid if there is humidity, and in common use in verbal and written forms.
Don't disregard "hot" just because of its simplicity.
The other answers here are good; particularly "boiling", "blistering", and "scorching", but I feel that most of the words here are used more in descriptive writing than in casual conversation (based on personal experience; not concrete evidence).
If I were to start up small talk with, for example, a person waiting at a bus stop, or if I were to walk outside and comment on the weather to my neighbor, I would generally say:
Cold: It is freezing out here!
Hot: It is hot out here! (I know this is boring and perhaps obvious, but emphasis on "hot" will convey the intensity as much as "freezing" does.)
Hot: It is hot as Hell out here!
Hot: Damn, it's hot!
You can use analogies, such as:
- It's like an oven out here today!
You can add intensity with incredulity, e.g.
- I can't believe how hot it is!
You can also qualify "hot" with an adverb to increase intensity:
It is incredibly hot out today!
It is insanely hot out today! (colloquialism)
It is ridiculously hot out today!
Or if it's already understood that it is hot (e.g. the person you are speaking to is outside with you, perhaps sweating), things as simple as:
Can you believe this?
Where did this come from?
It's crazy out there! (esp. if you say this upon walking indoors, sweating)
If indoors or in a cooler space you can also use the contrast with the cooler environment to convey the heat, for example:
Thank God for air conditioning!
Wow, it feels good to get out of that heat.
I'm not leaving this room until winter! (when in a cool room on a hot day)
However, when writing, where more poignant words are more commonplace than in spoken conversation; words like burning, scorching, boiling, etc. are very good.
In general, nearly any word or phrase that brings one of the following to mind will be understood as conveying intense heat:
Melting / Boiling / anything else that is a consequence of high heat (e.g. "blistering", "scorching", etc.)
The word "hot" itself does go a long way on its own, though, and shouldn't be overlooked.
How about “torrid”?