Humidity and wind are the killers when we talk about tolerating cold. A temperature of -20 C (-4 F) on the seashore in Finland is far worse than -30 C (-22 F) in central or northern Finland, where the climate isn't humid.
If it's calm, dry -20 C weather, you can easily go to get the firewood from the shed or see the dog take a pee wearing just a t-shirt and sweatpants, but with high humidity and the slightest wind you start to shiver in 30 seconds.
Feeling cold is also surprisingly much a mental thing.
Then again, I don't like too warm weather. When it's over 25 C (77 F) my batteries start to fail. At 30 C (86 F) I pull the curtains down and don't feel like going out at all, I feel so uncomfortable.
The whole temperature thing is strange. Think of how narrow tolerance we humans actually have. It sounds like the feared global warming of 3-5 degrees Celsius isn't so much, but if our body temperature rises 3 C, to 39,7 (103 F) we are seriously ill and immobilised, two degrees more and we're dying.