What does exclamation point mean on control panel of Hyundai Elantra?

I saw this on a Hyundai Accent I rented, was told it is for tire pressure being low. If its extreme cold weather this light comes on sometimes because the tire pressure decreased. First few days I drove car in 30ish degree weather it was not on, but this morning when it was 12 degrees this light came on. Supposed to go back up to 40 degrees in a day or two so if the light goes off I assume that is the issue, otherwise check if tires are low and need air.