LIMA: Kylie Jenner, the fashion model and younger half-sister of Kim Kardashian, was forced to use an oxygen mask after suffering difficulty breathing during a trip to the Peruvian city of Cusco, high in the Andes.

Jenner, 19, posted pictures on Snapchat social media showing her being treated with an oxygen mask in her hotel room in the historic mountain city.

"At this altitude of 11,000 feet above sea level, you can feel nauseous, have headaches, feel like you´re having the worst hangover ever," said a paramedic treating the cosmetics mogul in the video she posted. "Kylie´s getting oxygen so she´ll feel better."

The pictures showed the reality TV star -- whose own show, "Life of Kylie," will debut this summer -- wearing a red track suit and joking with the paramedic.

Caused by a lack of oxygen at great heights, altitude sickness results in severe headaches and nausea.

Jenner and her mother Kris had arrived in Cusco on Tuesday hoping to shoot footage for the reality television series "Keeping Up with the Kardashians." They earlier visited the Peruvian capital Lima, where they attended a charity event for children with cleft palates.

The pair later intended to visit the ruined Inca city of Machu Picchu in the mountains close to Cusco, local news reports said.