Spectators at President-elect Barack Obama's appearance tomorrow should dress to spend hours in subfreezing temperatures.
After single-digit lows early this morning, forecasters were predicting a high of only 24 degrees tomorrow in Baltimore - about 15 degrees below normal for this time of year.
Sunshine won't help much. The weak, mid-January sun will be dropping behind the city's skyline, toward a 5:10 p.m. sunset, and temperatures will be falling by 4 p.m.
Winds will be light, but with little physical activity for several hours, people in the crowd may begin to feel very cold.
"If you think you have enough on, put on another layer," said Dr. Stephen Schenkel, director of the emergency department at Mercy Medical Center, three blocks from the event. The entire hospital is on alert, with extra staff and a surgical team ready for whatever the day brings.
Traffic restrictions and crowds will prevent people from dashing to warming tents or their cars. "Once you're chilled and shivering, it's probably too late to look for a place to go," Schenkel said, noting that young, healthy people can endure the cold longer than older people or those with medical conditions.
The National Weather Service advises anyone outdoors in the cold for extended periods to wear several layers of loose-fitting, lightweight, warm clothing. Wear wool, not cotton, and remember your long johns. Your body will warm the air trapped between the layers, and that will provide insulation.
If you're too warm, you may perspire, and the dampness may chill your body, experts warn. If you start to sweat, remove a layer.
Outer garments should be tightly woven, water repellent and hooded. Add a watch cap under the hood. We lose half our body heat through our heads.
Wear warm, insulated shoes with light socks under heavier socks. Cover your mouth with a scarf or balaclava to warm your face and protect your lungs from extreme cold. Mittens, snug at the wrist, will keep your fingers warmer than gloves.
Unlike at a Ravens game in the cold, Schenkel said, "one of the advantages is people will be able to stand up and move around." So keep moving to stay warm.