A BBC crew filmed the tusked beasts spraying themselves with water that they had stored in a reservoir in their throats several hours earlier.
Although this skill for storing water was first documented 100 years ago, the team believes this is the first time it has been filmed.
It forms part of Natural World's Elephant Nomads of the Namib Desert programme.
Cameraman Martyn Colbeck, who has spent the last two decades filming elephants, said: "Elephants normally drink every day, but the desert elephant has adapted to go up to five days without drinking.
"Just behind the tongue they have this little pouch called the pharyngeal pouch. This is an area that is used partly in communication - it allows the elephants to have all of the deep calls, but they can also store several litres of water in it.