Many parts of the world don't have AC, and many people in those parts are not depressed.

Source: it's 22h00 here and its probably about 28C in my bedroom now. The walls are radiating heat into the room after baking in the sun the whole day. All my windows are open and ceiling fan is on. I'll be sleeping on top of a towel tonight as to not destroy my mattress.

I'm definitely not depressed... I think.

<hot-or-not> That's HOT!

Dry or humid heat?

If he's complaining about 28 C it's a humid heat. 28 C dry needs covers

Maybe I just have bad heat tolerance, but complaining that 28C indoors is hot seems normal to me?

Relatively dry thank dog. I hate humidity.

Depressive seasons are often associated with Winters where people are stuck inside in gloomy weather, lack of daylight etc

Here in Australia, summers are usually associated with happiness, social gatherings, beach, BBQ's

The article talks more about self regulation regardless of outside temperature influence.

The article talks about self-thermoregulation — so I don't know if those would exactly be correlated.