For those currently huddling for warmth in Texas and other places, do not use the “terracotta pot hack” bullshit.
No, putting a small pot over a candle is not going to heat your room.
You are not magically increasing the amount of energy in that system, this is not alchemy. All you’re doing is increasing the surface area that the heat can radiate from, and keeping the heat at that surface for longer due to the pot being a poorer conductor of energy than the surrounding air. Terracotta, like most non-glazed clay, is an insulator, not a conductor. Nor does it generate any additional energy itself.
All you’ll do is waste a candle and probably shatter the pot.
You may be able to more effectively heat your hands using it, since you’ll spread the heat and slow the dissipation. But, I wouldn’t consider it an overly efficient approach. You’d likely be able to generate the same amount of heat through friction and covering. It would be better to just wrap up your hands, as an exposed hand and wrist will continue to radiate away heat, likely at a greater or at least similar rate that the pot would. Meaning you’d likely still have a net heat loss.