Humans, as well as all air-breathing vertebrates, have a “diving reflex” which preferentially distributes oxygen stores to the heart and brain, enabling submersion for an extended time. The reflex is triggered by wetting the nostrils and face while holding one’s breath. – WTF Fun Facts
Source: Diving reflex – Wikipedia
wudu
In Islam, before every worshipping people wash nostrils and face called vudu, 5 times a day. 😉