Rüedi rose to fame around the world after having treated the Scottish author Robert Louis Stevenson in the winters of 1880-81 and 1881-82.

Stevenson praised Rüedi in the dedication of his poetry collection Underwoods (1887) as "the good genius of the English in his frosty mountains".

In 1867 Wilhelm came for a visit to his home village Zizers (Graubünden) and suggested his brothers Carl and Paul to follow him to America.

On December 24, 1874 Carl Rüedi received a call as a district doctor at Davos, Europe's leading winter health resort (beside St. Moritz) in those days.

On February 26, 1875 Carl Rüedi, together with two other representatives of the Rhätia hotel, was elected into the managing committee of the newly founded health resort club.

Rüedi's therapeutical successes were due to a combination of medical competence and the high-Alpine climate of Davos (altitude 1.560 m / 5,118 ft) with its cool, clean and dry air.

Rüedi impressed by exact diagnoses, an extraordinary delicate ear when auscultating the respiratory tract and a profound knowledge of all kinds and stages of lung troubles.

To let his competence take effect under less exhaustive conditions he emigrated to the US by the end of April 1891 and opened a doctor's office at Denver (Colorado).

Apart from a sanatorium in the hamlet of Hygiene (Boulder County, Colorado) (altitude 1,553 m / 5,095 ft) which Rüedi visited in October 1891 there only existed primitive camps of covered wagons and tents or isolated pensions and hotels.

[17] Yet in the year of his arrival in America Carl Rüedi was elected a fellow of the American Clinical and Climatological Association (ACCA).

In its early years the ACCA mainly aimed at treating tuberculosis patients by sojourns in a suitable climate.

In his second lecture (A Peep into the Future, with Respect of pathological-anatomical Researches) [16] Rüedi criticized the one-sided sympathy of his medical colleagues for the cytopathology.

Rüedi was convinced that analysing the blood serum would provide physicians a valuable means to forecast the „degenerations” in the cells of the respective person which are to be expected in the near future.

By the introduction of a limited number of licenses to local physicians the exercise of the medical profession had become so regulated that even a capacity like Rüedi had no chance of opening a doctor's office there.

In the winter of 1896-97 Rüedi started to practice as a private doctor at the Grand Hotel Arosa (nowadays Robinson Club).

Rüedi seriously worried about his financial income and started to commit himself in raising the attractiveness of Arosa as a health resort.

In his spare time Rüedi was active in organizing and timekeeping the wintertime sledge races which were first and foremost arranged for the entertainment of tourists.