What you're probably noticing
The furnace kicks on fine. It runs for ten minutes, seems normal, and you stop thinking about it. Then on the coldest nights of the year, the ones where the system has to run for hours straight instead of in short bursts, something changes. Maybe the air coming out gets cooler toward the end of a long cycle. Maybe you hear a new rattle or a faint burning smell that wasn't there an hour ago. Maybe the furnace just shuts off on its own and won't restart until it's cooled down.
This is a pattern specific to Springfield winters. We don't get the kind of deep, unbroken cold that some parts of the country do, but we get enough swings, a week in the 50s followed by three days in the teens, that a lot of furnaces here rarely run long enough to reveal a problem until a true cold snap forces them to.
Why sustained load is different
A short cycle puts almost no stress on a system. Parts heat up, the thermostat is satisfied, everything shuts off before anything gets pushed close to its limit. A sustained run, four, six, eight hours during an arctic blast, is a different test entirely. Heat exchangers expand further. Blower motors run hot. Any marginal electrical connection has more time to loosen or arc. Any restricted airflow has more time to cause a real problem instead of a minor one.
This is why a furnace can pass every check in November and then struggle in January. The fault was always there. It just needed hours of continuous operation to show up.
More on this from The Furnace Faults That Only Show Up Under Sustained Load.
What's common in this area's housing stock
A lot of Springfield's housing, especially in the older neighborhoods around the center of town and in some of the postwar additions further out, still runs furnaces and ductwork that are decades old, sometimes original to additions built in the 60s and 70s. Ductwork in these homes was often sized for a smaller or less efficient unit and never adjusted when the furnace was replaced. That mismatch doesn't matter much on a mild day. Under sustained load, it forces the furnace to work harder than it should, and that's when overheating-related shutdowns and cracked heat exchangers tend to appear.
Newer construction in and around Springfield isn't immune either. Tighter building envelopes mean less natural air leakage, which changes how a furnace's airflow and combustion venting behave under long runtimes. A system that was installed correctly for a loosely sealed house can start short-cycling or alarming in a tightly sealed one once it's asked to run for hours at a stretch.
What you can check yourself
Start with the filter. A dirty filter is the single most common reason a furnace struggles under long runtimes, and it's also the easiest thing to fix. If you haven't changed it since fall, change it now, before the next cold snap, not during it.
Walk your registers and make sure none are closed or blocked by furniture or rugs. Closing off rooms to save money actually increases strain on the system during long cycles, since the air has fewer places to go. Check that your outdoor vent and intake pipes, if your furnace has them, aren't blocked by snow, ice, or debris. And listen. A new noise that only shows up after the furnace has been running a while, a hum that gets louder, a tick that speeds up, is worth paying attention to and writing down when it happens.
Where it stops being a homeowner job
If the furnace shuts off and won't restart until it cools down, that's a limit switch doing its job, and it's telling you something is actually wrong, not just annoying. Don't keep resetting it and running the system anyway. A cracked heat exchanger, a failing blower motor, or a wiring issue that only shows itself under heat and time is not something to diagnose by trial and error, especially with carbon monoxide risk in the mix.
Any burning smell that doesn't fade within a few minutes of startup, any smell of gas, or any shutdown that happens repeatedly on long runs is the point to call someone who can put a meter and a combustion analyzer on the system rather than guess. Faults that only appear under sustained load are, by nature, hard to catch during a quick inspection. They need to be tested under something close to real winter conditions, which usually means a technician running the furnace deliberately long enough to watch it do what it does at hour three, not just what it does at minute ten.