Cold hands don’t cause false pulse oximeter readings. The readings are just different. There was an experiment named Effect of Local Limb Temperature on Pulse Oximetry. Here the scientists were able to find out that the SpO2 (peripheral capillary oxygen saturation) and SvO2 (venous oxygen saturation ) readings change with respect to the limb temperature.
How does oximeter measure the blood oxygen level
Oximeter sends a small beam of light with a specific wavelength to measure the oxygen level. The more the blood, the more oxygen will be attached to the hemoglobin. If your hands or limbs are cold, it means that there is less blood and your oximeter reading will be less than the normal.
What happens when the body is cold
When the body temperature starts to decrease than the optimum, this is called hypothermia. Unlike in healthy people, a decrease in body core temperature of 2°F (1°C) can negatively affect the critically compromised patient.
In case of healthy people
However, if you are a healthy person and your body gets cold due to less temperature in your vicinity, then you can do warm-up exercises or rub your both hands for some minutes. This will make your body to generate heat and oximeter will give you correct readings
Ear lobe oximeter
If you have consistently low blood pressure and your body can’t maintain its temperature due to some pathology, then you can go for ear lobe clip oximeter. Oximeter in such cases can help but there are limitation and only doctors can provide you the proper medical care.
zeppo says
patient sitting, hands at rest, oximeter provides reading.
patient sitting, hand raised, no reading.
lower hand, reading returns.
raise hand, reading vanishes.
LOW ON BLOOD?
Todd says
I have the exact same phenomenon with my fingers.
One of my doctors, while I was hospitalized for pneumonia, suspected hypovolemia (low blood volume).
I only learned this by reading his notes in the medical record weeks after the fact. No mention of it or testing was done while I was there.