Ask anyone who fits heating systems for a living what they do in their own home in January, and the answer is consistent: they do not heat the whole house.
"The thermostat heats every room, the loft hatch, the hallway, the spare bedroom nobody has opened since August," one told me. "You are paying to warm cubic metres of air. The person is a very small part of that."
The arithmetic most of us never do
A typical central heating system draws several kilowatts. Running it through an evening to keep one person comfortable in one room is, in energy terms, close to absurd — and it is the largest line on most winter bills.
The alternative is not sitting in the cold. It is moving the heat closer to the person. Electric blankets have done this for decades; what changed recently is that the same idea became wearable and cordless.
What actually changed
Carbon-fibre heating elements are thin, flexible, and survive being bent thousands of times. Paired with the battery chemistry that powers a cordless drill, they hold a steady temperature for most of an evening while drawing roughly what a phone charger does.
The practical effect is that you can be comfortable in a room several degrees cooler than you would otherwise keep it, and the thermostat never comes on at all.
What to look for
Panel placement matters more than anything else: chest and mid-back, not sleeves. Warming the torso is what stops the rest of you feeling cold.
More than one heat setting is close to essential — a single-temperature product is either too much or not enough within twenty minutes. A removable battery matters too, because without one you cannot wash it and cannot replace the part that wears out first.
Treat runtime claims with mild suspicion. Eight hours on a low setting is realistic; figures far beyond that usually assume a setting nobody uses.