Buzz Aldrin, the second man to walk on the moon, is recuperating at a New Zealand hospital after being evacuated from the South Pole.

Aldrin, who's 86, was visiting Antarctica as a tourist when he fell ill. He was flown to Christchurch from McMurdo Station, a U.S. research center on the Antarctic coast.

Tour company White Desert says Aldrin has fluid in his lungs, but is responding well to antibiotics and in stable condition. He'll remain hospitalized overnight for observation.

Aldrin and Neil Armstrong became the first men on the moon, on July 20, 1969. Armstrong died in 2012.

Just three weeks ago, Aldrin was at NASA's Kennedy Space Center in Florida for the unveiling of a new astronaut exhibit.