When you get cold, your body redirects warm blood toward your vital organs. To reduce heat loss, it narrows the small blood vessels in your hands, feet, ears and nose, making those areas prone to frostbite, a freezing injury that can damage skin and underlying tissue.

We have two relatively new types in winter weather warnings, called extreme cold warnings and cold weather advisories. Let's look at what those mean, and where they are in effect this weekend.

Boston will fall under a cold emergency Friday and Saturday with wind chills set to reach as low as -10 degrees, Mayor Michelle Wu announced. “During these harsh conditions, please plan ahead to stay warm,

Chicago temperatures plunged well below zero Friday morning, with some places feeling as cold as -40 degrees. While an Extreme Cold Warning has expired, a Cold Weather Advisory is in effect until Saturday morning.

Extreme cold warning (take action as soon as possible): This is issued when extremely dangerous cold temperatures or wind chills — 5 degrees or below — are expected or occurring. Residents should avoid going outside, though if you have to you should dress in layers, cover exposed skin and make sure at least one other person knows your whereabouts.

On Thursday at 1:36 p.m. a cold weather advisory was released by the NWS Wakefield VA valid from Friday 8 p.m. until Saturday 10 a.m. The advisory is for Western Currituck and Eastern Currituck as well as Northampton,

Systematic reviews show cold water immersion reduces soreness and boosts 24‑hr recovery. Emerging studies suggest mood, stress and sleep benefits but evidence remains limited. Start with mild temps, short durations; seek medical clearance if cardiac risk.

As temperatures plummet across the U.S., pet owners may need to reassess the safety of their dogs being outside.