Among people having easy access to water, extreme conditions of
dehydration are rare. During everyday drinking, liquids are perceived
as being refreshing mainly because of their ability to alleviate
oropharyngeal symptoms. Indeed, cold liquids are refreshing in part
because they lead to mouth and throat wetness and in part because
they enhance salivary flow due to cold stimulation. This may partly
explain why cold or thin liquids are perceived as refreshing, while
astringent and thick liquids seem to dry the mouth even though the
wetting effectiveness of astringent solutions is as efficient as that of
water under dry-mouth conditions.