The cooling procedure should only be applied to hands, feets, or the face and not the whole body. The goal is to bring the body back to normal temperature in order to perform ( do more reps ) than what you would typically be able to if not cooled.
For example you could put your hands in cold (not ice cold ) water for a short period of time between set ie. 2 minutes.
You can find the podcast on youtube where he goes much deeper into the details of the research end the experiments.
The Process of lowering body temperature post workout will also improve your recovery, but as for the experiments during workouts, lowering the body temperature does not mean going into an ice bath or doing cryotherapy and those will probably be counter productive as science tells us.
Fruit for thoughts...