Make sure to have weather appropriate clothing and get outside even when it is cold. Anything short of sleet/ice/blizzard is perfectly fine for the average mobile person getting out for at least a short walk outside as long as they are dressed appropriately and there aren't massive drifts.

If mobility is an issue then getting out when it is cold, but not dangerously slick, is still a good idea.

One thing most people don't know is that cold weather gear needs to match the weather and the level of effort being made. Walking in wind requires a lot more insulation and wind protection than shoveling snow without wind because effort heats up and sweating is dangerous when it is cold. Keeping dry is critical, both from external moisture and from sweat!