Nude Dog Rescuer -- My Lungs Were Collapsing!

3/20/2009 12:40 PM PDT BY TMZ STAFF
We barely noticed Eric Nies with his clothes on in New York yesterday -- but the "Real World" doggy rescuer claims he's used to getting naked and jumping in freezing cold water because he frequents bathhouses ... no, not that kind.

The naked pooch rescuer finally explained why he felt compelled to strip down and save his friend's dog -- then he showed off the best way to raise your body temp after diving buck naked into freezing water.

Eric Nies: Click to launchAnother way to raise your body temp -- check out the photo gallery.