Doctor Dissects the Wim Hof Method - Cold Hard Science Analysis

How hyper-ventilation reduces the sensation of pain and that the placebo-effect affects the immune-system;

Quotes

A rise in pH to around the levels achieved by hyper-ventilation can actually de-active them [the ASIC3], effectively improving the pain-threshold. – https://www.youtube.com/watch?v=D6EPuUdIC1E#t=20m31s

That’s exactly what the placebo effect is: Mild changes in immune-system response can be observed purely based on a persons believe about what the outcome will be. – https://www.youtube.com/watch?v=D6EPuUdIC1E#t=22m21s