It's a clear and sunny—but cold—opening day for the Yankees today, and the MTA is giving riders a chance to head to Yankees Stadium in vintage style. A Lo-V (low-voltage) train is leaving 42nd Street-Grand Central at 11:30 a.m.

The train consists of four cars from 1917; these cars were in use into the 1960s. You can get the Nostalgia Train on the uptown express platform at 11:30 a.m.

For those of you heading to the game, let's say this again: It's gonna be really cold.

Dr. Robert Glatter, emergency physician at Lenox Hill Hospital, gave us some tips. "It's really important to wear layers in this weather. Wear a hat and gloves and cover your face," he said, emphasizing the significant heat loss from the head. "A full face mask, where you protect your ears and scalp" would be ideal.

"Older people and young children are apt to lose heat much faster," Dr. Glatter continued. "When you're older, it's hard to regulate temperature, which puts them at risk of hypothermia."

Adults should (obviously) also bundle their children. He said, "Kids won't notice they're cold because they're having too much fun."

Another group at risk while watching a cold weather game are those taking anti-psychotic, anti-depressants or sedatives because those medication affect how one regulates temperature.

Actually, anyone can potentially develop hypothermia if sitting in 40 degree-or-below conditions for a prolonged amount of time, if you're sitting in the sun and sweating. Dr. Glatter recommends, "Drinking warm fluids"—and avoiding alcohol. "Alcohol causes blood vessels to dilate and it speeds up heat loss." Water is a fan's best bet to stay hydrated; coffee will dehydrate you too much, and some sports drinks have a lot of caffeine.

So, wash down your hot dog with water if you dare unwrap your scarf from your face.