How do Americans deal with the sweltering summers AND freezing winters there?

I'm from the UK and I visited the US (Michigan) last January and it was biting cold with blizzard after blizzard and in some days, the temperature dropped to minus 20.

Then I went again last July thinking that if the winters are like that bad the summers must be pretty mild and nice.

NOPE, I went there in July, and it was swelting with the temperature routinely going above 30 degrees and on top of that it was humid.

I mean I get that some people can deal with extreme heat or extreme cold because it's like that where there from but how can anyone cope with both?

How do Americans deal with the sweltering summers AND freezing winters there?
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