1. is it true of EVERYONE that when you first put the oxymeter on it will be lower than it will be after a few seconds and is this because my finger may be cold? 2. If one has begun oxygen support [night times and when out and about in the city doing brisk walking] and there has been no cause established, should one expect to live longer or less? I started on oxygen at 69 when a sleep apnea test showed low oxygen all night. No apnea though.