Oh, who wants to ride the subway anyway... but we do

For New Yorkers who have to ride the subways all the time, the biggest threat to their health seems to be from the noise levels. Children especially.

Studies done by researchers at Columbia University show that just being in  a crowded subway car raises all kinds of physiological factors associated with stress..

However, for the best tips for tourists (maybe even useful for natives), try reading this on "How to Ride the Subway" for very down to earth practicalities..

http://www.wikihow.com/Ride-the-New-York-City-Subway

If you know someone coming from out of town, you might suggest they read this before they come so they know what to expect...