Due to me disliking the dry air the central heating provides I came up with this thing (years ago). When it's moderately cold 2 of these, what I call, 'poor man's stoves' are sufficient to warm the attic (the room on the top floor/my bedroom) that much there's no need for the central heating's help to warm up the room. Yeah, when it's too cold I'll turn the heating on but also 2 of these will provide the room with some warmth (and moist).
I boil some water, light 2 tea-lights, pour the hot water in the top can and..
(.. my nips feel comfy
)