A TERRIFIED tourist has been rescued in Crete after floating for 21 hours on the open sea on an inflatable sun-bed that was swept away by a strong current.

Russian medic Olga Kuldo, 55, was saved after a border patrol plane checking for illegal immigrants spotted her more than 11km offshore, The Sun reports.

She floated through one night and was reportedly fried alive by the hot sun the following day. She needed hospital treatment for exposure and resulting heart problems.

The woman from Zelenograd, near Moscow, had been staying with her husband Oleg, 59, and daughter Yulia, 28, at the resort of Rethymno on the north of the Greek island.

They alerted rescuers after she failed to return to her hotel room after a late afternoon swim.

But it was 21 hours later that she was spotted from the air after a huge boat and jet ski search failed to locate her.

A rescue vessel brought her back to shore and she was rushed to hospital with “heart problems” and “hypothermia” after suffering from exposure and sun stroke.

Her relieved daughter posted on social media: “Miracles happen.”

She said her mother, an ultrasound diagnostics doctor, had been “burned to ashes” by the daytime sun before the EU Frontex agency plane spotted her.

A local report on the island said she was on her sun-bed “when she was carried away to the open sea so she could not be seen from the beach”.

It is unclear if she fell asleep but reports say she was carried away by a “strong current”.

She was kept in hospital overnight. Local reports described Ms Kuldo as “lucky” to survive.

“She stayed alive despite a cold night, strong wind, occasional rain and even a small thunder storm,” a local outlet reported.

Her body temperature was as low as 32 degrees — normal is 37 degrees — causing hypothermia, it was reported.