Which of the following may affect the measurement of oxygen saturation?

While poor exercise habits can affect overall health and potentially impact oxygen levels in the body, they do not directly influence the measurement of oxygen saturation at the time of testing. Oxygen saturation readings are immediate assessments and not influenced by an individual's exercise history.

Dirty hands can introduce contaminants, but they do not typically affect the accuracy of oxygen saturation measurements. Pulse oximeters read light absorption through the skin; therefore, surface dirt does not significantly obstruct the light needed for accurate readings.

Drinking a hot beverage may temporarily affect peripheral circulation or cause vasodilation, potentially impacting the readings momentarily. However, it does not have a direct and significant effect on the measurement of oxygen saturation like fingernail polish does.