I seem to remember that the colder you are...the better...slows down brain activity.
I believe they lower your body temp on purpose, to prevent brain damage...
Cardio Pick-Me-Up - Forbes.com
They turned to cooling. There is a growing acceptance among doctors throughout the U.S. that cooling a patient's body temperature can reduce brain damage as well as other bodily damage. When Buffalo Bills football player Kevin Everett suffered a severe spinal cord injury last month, ice cold saline was pumped into his veins to lower his body temperature, according to news reports. Although patient privacy rules have made details scarce, doctors are speculating that the cooling may have helped protect Everett's spinal cord. Other early studies have shown that bringing down body temperature helps patients who've suffered from heart attacks and strokes