An overheated South Australian koala has been filmed taking part in an age-old Australian backyard tradition – lying under the sprinkler on a searing summer day.

With Adelaide temperatures in the thirties on Tuesday, the stressed-out koala was soothed by Steven Wiltshire, who positioned a sprinkler so that it would reach the lower branches of a nearby tree.

"I figured he was probably hot and dehydrated so I set up one of my lawn sprinklers that hasn't been used in forever, such that water hit the lower reaches of the tree," Mr Wiltshire told Mashable .

When he later returned to the tree, Mr Wiltshire noticed the koala had come down to a lower branch and filmed it lounging.

By the morning, the koala had moved on.

Several videos of overheated, dehydrated South Australian koalas have gone viral this summer.