Quick Answer: Indoor heating adds a third environment to a day that your layering was built for two of. Outdoors is cool, indoors was cool, and now indoors is warmer than the summer days you dressed for. The layer count is not the problem — the fabric weight of the base layer is, because that is the one you cannot remove. Switch to a light base and put the warmth in removable outer layers, and the heating day stops being a problem.

This is why the first heated week of the year feels harder to dress for than midwinter.

Midwinter is consistent. This week is not.

Why does heating break a layering plan that was working?

Because it inverts the relationship between indoors and outdoors.

For most of the year, indoors and outdoors differ by a manageable amount, and layering handles it. Through late summer, indoor and outdoor temperatures track each other reasonably closely. Through early autumn, indoors is cooler than it was and outdoors is cooler still, so a warm base layer plus a light jacket works beautifully.

Then the heating goes on, and indoor temperatures jump — often to 21 or 22°C, sometimes higher in older buildings with poor control — while outdoors is sitting at 10 or 12. The gap doubles overnight.

The crucial part is which direction it broke in. Your layering was built to add warmth on top of a warm base. Now you need to remove warmth indoors, and the warmth is in the layer against your skin.

So you can take off your jacket and your cardigan and you are still too warm, because the merino base layer you chose for the cool mornings is still there and it is not coming off.

The fault is in the base, not the count.

Why is the first week the worst?

Because nothing is calibrated yet — including the buildings.

Heating systems are frequently over-set when first switched on. Thermostats get turned up in response to a cold week and not turned back down. Radiators that have been off all summer are unbalanced. Buildings that were pleasant in September become genuinely hot in the first week of October and then settle.

Meanwhile the outdoor temperature is still swinging widely — a 20-degree morning and a 10-degree one in the same week is entirely normal at this point in the season.

So you have unpredictable indoors and unpredictable outdoors, in the same week, which is the hardest combination there is. Midwinter is much easier: outdoors is reliably cold, indoors is reliably heated, and you dress for a known gap.

There is also an adaptation factor. Your own perception of temperature shifts over a couple of weeks as the season changes. The 12°C morning that felt cold in September feels mild by November, with no change in what you are wearing.

Which is worth knowing before you buy anything. The problem is partly the week, and it will partly solve itself.

What should actually change about the outfit?

The base layer’s fabric weight, and where the warmth lives.

The principle is straightforward: all removable warmth, minimal fixed warmth. Whatever is against your skin should be light enough to be comfortable in a 22°C room, and everything above it should come off.

In practice that means:

Base: a light layer — fine cotton, a thin jersey, a light knit. Not a mid-weight merino, not a brushed anything, not a thick ribbed long sleeve. This is the change that matters most.

Mid: the warmth goes here, and it must be genuinely removable in a way that leaves you presentable. A cardigan, an overshirt, a light knit. Something you can take off at your desk without it being an event.

Outer: the weather layer, which comes off at the door.

Compare that to the failing version, which is mid-weight base plus jumper plus coat. Two removable layers and a fixed one that is too warm — so indoors you end up at mid-weight base alone, which is still too warm, and there is nothing left to take off.

Same three layers. Completely different day.

Myth vs Fact: Dressing for the Heating Season

Myth: More layers means better temperature control.

Fact: Removable layers give control. A fixed warm layer gives none, regardless of how many things are on top of it. Three layers with a light base beats four with a warm one.

Myth: Natural fibres solve it.

Fact: Merino is genuinely excellent at handling a range of temperatures, and a mid-weight merino base in a 22°C room is still too warm. Fibre choice helps at the margins; fabric weight decides the outcome.

Myth: You should dress for the coldest part of the day.

Fact: You should dress for the part of the day you spend the most time in, which for most people is indoors, and then add for the commute. Dressing for the 7am walk and then spending nine hours in a heated building is the wrong optimisation.

Myth: A big coat solves everything.

Fact: A warm outer layer is exactly the right answer, and it only works if the layers underneath are light. A big coat over a heavy jumper is the classic overheated commute.

Myth: This is just a fussy problem.

Fact: Here is the practical stake — arriving somewhere already sweating in a base layer you cannot remove means you spend the rest of the day in damp fabric, which then makes you genuinely cold on the way home. The transition day is where the sweat-then-freeze cycle actually starts, and it starts with a base layer chosen for the wrong environment.

How to build a heating-season transitional outfit

A formula that survives all three environments.

Start with the indoor temperature, not the outdoor one. Ask what you would wear in a 21°C room all day, and make that your base. For most people that is a light long-sleeve or a short-sleeve with something light over it.

Put every bit of warmth in something removable. Cardigan, overshirt, gilet, scarf. Two mid layers is often better than one warm one, because it gives you an intermediate setting.

Choose an outer layer that handles the actual weather — wind and rain matter more than warmth at this point in the season, since the commute is short.

Use a scarf as your adjustment dial. It is the most thermally effective and most easily removed item available, and it takes up almost no bag space.

Check the fabric weight of your base by hand. If it feels substantial, it is too warm for a heated room. This is a more reliable test than any label.

Carry a bag that can hold a layer. The whole system depends on being able to put something away, and a small bag quietly forces you to wear everything.

Pick shoes for indoors. Boots that are correct for a cold morning are frequently too warm for a heated afternoon, and feet are where overheating is least noticeable and most uncomfortable.

And give it two weeks. The buildings settle, your perception adapts, and the week that felt impossible becomes ordinary.

FAQ: Heating Season Dressing Questions, Answered

What temperature should I actually dress for?

Dress the base for around 21°C and layer for whatever the outdoors is doing. Most heated indoor spaces sit between 20 and 23.

Is merino still worth it?

Very much, in a light weight. Fine merino handles the sweat-then-cool cycle better than almost anything and is comfortable across a wide range. The problem is mid-weight merino, not merino.

What about the commute specifically?

The commute is the shortest part of the day and the part people over-dress for most. Be slightly cold for the walk to the station rather than slightly warm — the walk is fifteen minutes and the office is nine hours.

How long does this awkward period last?

Usually two to three weeks, until buildings settle their heating and outdoor temperatures become more consistent. It genuinely does get easier without you doing anything.

Does this apply to working from home?

Differently, and often more manageably — you control the thermostat. The issue at home is usually the opposite one, where heating a whole house for one person makes a warm base layer the sensible choice again.

TL;DR:

• Heating adds a third environment, and your layering was built for two
• The problem is the fixed base layer’s fabric weight, not the number of layers
• Dress the base for a 21°C room and put all the warmth in removable mid and outer layers
• The first heated week is worst because buildings are over-set and outdoor temperatures still swing
• Under-dress for the short commute rather than over-dressing for the long indoor day

Swap the mid-weight base for a light one and add a cardigan. Same three layers, same bag, and the day the heating comes on stops being the worst-dressed day of your year.