In New England my dad always kept the house cold (not 50F) while my college dorm (also in New England) was kept toasty.

Going back and forth over winter break I definitely noticed a productivity shift being some place I was warm and comfortable.

Perhaps there are less noticeable psychology benefits for it being cold but I do not think being uncomfortable and dealing with it is a long term strategy for success. And probably completely impractical if you live with other people in the same house.

When your core cools, your body will react by reducing bloodflow to your hands and feet (which are basically radiators) to preserve heat for your core. Generally, dressing warm to keep your core warm should help keep your hands and feet warm too, but of course there will always be a temperature gradient.

If that isn't sufficient, there are still cheaper ways to deal with it than adjusting the furnace. A low power radiative space heater (the sort with a reflective dish) can be very efficient at heating up the person it's pointed at without heating up the whole room. Having a warm drink to pick up and sip on also helps; it'll warm your fingers directly and also give your core a little boost of heat. Heated electric blankets are also extremely effective.

Also, cold walls mean condensation and then mold.

That happens when the cold walls are cooling down warm air, dropping the moisture out of that air. If you have a warm house and open all the windows in winter, you'll get condensation on the walls. If the house was cold in the first place, e.g. the walls and air are in a cold thermal equilibrium, you won't get condensation on the walls.

Bathrooms and kitchens are a special case, which can be addressed with ventilation. One of the upsides of keeping your home cool in the winter is it's much cheaper to circulate in new air from outside. You get to have fresh air all winter without paying to heat all that air up. I believe fresh air throughout the year has many health benefits.

It really depends. The air that you exhale is hot and humid. As soon as it touches the exterior walls, it will condensate. I'm talking about a house that is not insulated, but also does not leak air out (new windows with good seals). If it leaks some air out, then the condensation is very limited as outside cold air is dry in winter.

It might be like you said only if you don't use that room, or you have a big house so maybe you don't use most rooms and then you don't fill them with humidity from your own breath. Walls are cold but also dry.

Opening the windows in the winter is how you let all that humidity out.

> Opening the windows in the winter is how you let all that humidity out.

Absolutely, being able to open your windows is a big advantage of keeping your thermostat low.

When the inside of your home is warmer than the outside when there is cool weather outside, you don't have humidity, mold, and condensation problems.

You can, and also in the inverse situation; it depends on how the walls are built.

Fingerless gloves can help. A light beanie compensates for baldness, as does slippers on the feet.

Yeah, I can only do so much cold because of my hands.