We are now truly immersed - and it's the right word - in the full, awful steam bath season in much of North America.
Just to venture outside is to hit a wall of humidity that drains the spirit as it soaks the clothes.
Fortunately, though, America has embraced air conditioning with a vengeance.
If it's like a warm soup outside, the inside of cinemas and trains and stores is chilled to the point of discomfort.
Air conditioning in America seems like a necessity.
Hot-water bottles please
The old ways of cooling down are not the most effective
Europeans often arrive with a disdain for it - but quickly rush for the 'on' switch once the end of July and August arrive.
Although when the King and Queen of Britain stayed in Washington in June 1939, with the temperature in the sticky 90s F (high 30s C), they asked for hot-water bottles at the White House! Presumably, they were trying to make some point about British grit.
For the rest of us, air-conditioning is a necessity.
Not only is it an essential, but it's changed the economic and political way of life of the country.
The relocation of businesses in the south wouldn't have happened without it.
The rise of the South
A product of the chilled-down South
Would Atlanta or Houston or Miami have been able to hold their own against New York (where Summer is unpleasant but just about bearable without air conditioning)?
And would car-makers see Alabama as viable without it?
There's also a reputable argument that air-conditioning, by making the South economically viable, kept the South alive politically too.
One of the people who might thank air conditioning, accordingly, is President George W Bush.
And Democrats win only when they have a strong Southern association - like Bill Clinton from Arkansas.
Half a century ago, less than a third of Americans lived in the South; now it's more than half.
Do rugged Americans need to chill?
It wasn't always so.
For much of the first half of the 20th century, a debate raged in the United States about whether air conditioning would sap the strength of the nation.
It's now cool to live in the South
There were arguments and counter-arguments. Wasn't it the fortitude of the rugged American in extremes of climate that would make the greatness of the culture?
Or would American ingenuity in developing technology that could defy nature show how the New World would triumph over the Old?
It was a debate bathed in racist assumptions.
In 1915, the geographer Ellsworth Huntington argued that the tropics had a "dull, unprogressive population".
One of his followers went further, arguing that hot cities like Washington, New York and Los Angeles were doomed.
The cities of the future would be Detroit, Montreal and Moscow.
European immigrants were warned then that they risked losing their vitality in the American heat, a heat that allegedly had lost the South the Civil War.
This history has been written by Marsha Ackermann in a fascinating account, "Cool Comfort: America's Romance with Air Conditioning".
She reproduces a newspaper advert from 1949 that shows a Mexican sleeping in the dirt with the caption "temperature 102 degrees - production zero" and continuing "Why have most great inventions and advances in science and industry come from temperate zones?
"Because for centuries tropical heat has robbed men of energy and ambition. There was no air conditioning. So they took siestas, seeking relief from heat and stifling humidity," the advert claimed.
In the end, the air-conditioners won the day.
Air conditioning systems have boosted the US economy
In 1925, the Rivoli cinema in New York installed a new system at an astronomical cost of $100,000 - it paid for itself in three months.
Congress debated the matter in 1928 and decided for coolness rather than fortitude.
It introduced the cooling system and that gave a huge boost to air conditioning.
In 1942, Washington became the fist city where electricity consumption was higher in summer than winter.
Since then the boom of air conditioning, and the south, has continued.
As the British writer, Sydney Markham, put it: "The greatest contribution to civilisation in this century may well be air conditioning - and America leads the way".