We've been below freezing and in the teens to twenties for a few days. Not a situation that happens here very often.
Yesterday morning, I fired up the Explorer to let it warm up. After it was good and warm I jumped in to head off to buy cars - but NO HEAT! Ice cold air only. Turns out the antifreeze in the 215,000 mile Exploder had given up its ability to anti-freeze and my heater hoses and core were frozen. Luckily it thawed from the engine heat after a few more minutes and did not rupture. Of course I did not leave the driveway until it was toasty warm inside.
Dodged a bullet there.
I'm ready for summer.