We have entered an extreme cold snap, and Extreme cold weather and driving winds may freeze some things in your St Louis or St Charles home, that may not have under more 'normal' winter conditions. The main concern being water supply piping.
It may be news to some, that water is one of the few things to EXPAND when cooling (once it is past it's freezing point), around 9% ! That expansion literally pushes the fittings off of piping, or even bursts a sealed item like an exterior hose bib.
If you don't have frost free exterior valves and haven't drained the hose bibs (you've been lucky so far), the next couple days will likely be the fail point. Don't feel too bad, I find these type of valves un-drained on home inspections in St Louis County and St Charles County MO more often than not. Shut off the valve in the basement, and remove any drain plugs. Have a bucket to catch the remaining water in the line. Do this every fall, from here out.
Any sinks on exterior walls, and especially those with supply piping IN the wall, can be helped some by simply opening the cabinet below the sink to let some warmer air circulate closer to the piping. A heater for extreme cases. Don't catch the house on fire, though. A faucet left dripping (slowly) helps fight this freezing, too, as the motion of the water itself makes freezing more difficult. Main water supply piping in a crawlspace or otherwise exposed to the elements, may and probably should have heat tape installed (to the bottom edge, not 'wrapped' as I hear so often), and insulation. Make sure that is in place, and in working order, and plugged into a working receptacle. Maybe close off some of the venting to the crawlspace for a few days, as moisture is not the present concern.
Feel an interior draft? Chase it down and stuff a Kleenex or two in it, use a shim or worn down pencil as an applicator, depending on the gap. Loose windows? Tighten them up with some folded flat card stock, like political junk mail, cut and folded to desired thickness, and stuck between the window and stop, to hold the sash tight to the outside, hence tightening the gaps. Lay towels across leaky window meeting rails, sills, and door thresholds. Use shims to tighten tops and bottoms of loose / old doors, to close them tight, and maybe even hang blankets over them... and, of course, have it all fixed properly on a warmer day. The north/west sides are probably letting the cold in, and the south/east sides letting the heat out.
Good luck, and stay warm!