Relief of mouth dryness had been related to coldness of water in
several studies. For a given volume consumed, water at 5 °C is
perceived as more thirst-quenching than warmer (22 °C) water.
Eccles proposed that cold water is more effective than warm water in
reducing thirst in humans, because of the higher impact of cold water
on salivation. This idea was partly based on an earlier study
showing that water at 0 °C produced more parotid salivary flow than
did water at room temperature (22 °C).