 He attributes these feats to his Wim Hof Method (WHM), a combination of frequent cold exposure, breathing techniques and meditation.Hof has been the subject of several medical assessments and a book by investigative journalist Scott Carney.Hof was born in Sittard, Limburg, Netherlands as one of nine children, (in order of birth; Rob [1954], John [1955], Marianne [1957], Wim and Andre [1959-identical twins], Ruud [1961], Ed [1962], Marcel [1964], Jacqueline [1967]) Hof has six children, four of them with his first wife Marivelle-Maria (Also called "Olaya"), who died by suicide in 1995, a son, born in 2003 to his girlfriend, and a son born in 2017 to his last girlfriend.