NORRISTOWN, Pa. -

A Code Blue cold weather emergency has been declared for Montgomery County.

Based on a review of forecasts from the National Weather Service, the warning has been issued for the period beginning at 9 p.m. Saturday and continuing until 9 a.m. Tuesday.

Such cold weather declarations are made in the county when winter conditions pose a threat of serious harm or death to individuals without shelter. It is called when the combination of air temperature and wind chill is anticipated to be 20 degrees F or less.

The warning was issued Friday by Montgomery County commissioners, on the advice of the county's public safety department.

For cold weather information, check the Montgomery County Health Department website.