Don’t do it! It’s total bullshit! Obviously the experiment was not done with an athlete. I did it NOW and it destroyed my heavy training session. Protocol: soaking the palms of my hands in ice-cold water (water with ice and salt) for as long as I could bear it and immediately perform the bench press. Results: 1. The perception  of effort is GREATLY INCREASED (and not otherwise); 3. Concentric failure in the second rep of what wasn’t supposed to be even 90% of that day’s max effort; 4. Overall fatigue. One of the obvious conclusions is that it spoils any high performance athlete’s focus. You can’t keep focus while trying to control your hands inside a bowl of ice-cold water.

Here are the articles:

Stanford researchers’ cooling glove ‘better than steroids’ – and helps solve physiological mystery, too

Palm cooling delays fatigue during high-intensity bench press exercise.