Method and apparatus for providing reliable blood oxygen (Sa02) andheart rate measurements includes a chemical energy heating source inconjunction with a harness that is adapted to secure the chemical energyheating source and a pulse oximeter probe proximate to a region of the bodywhich is to be warmed prior to measurement. Preferably, the chemicalenergy heating source is in the form a mixture including a metal powder,which releases heat at a predetermined rate via oxidation of the metalpowder when exposed to the atmosphere. The apparatus may be designedto be reusable or disposable and can be used in a transmission orreflectance mode, or both.
