Two days after the first discovery, Hans Kammerlander and Reinhold Messner, two famous mountain climbers from South Tyrol happened to arrive at the site, and the photo of figure 1 shows them watching the Iceman.
Messner made a first guess at the age of the man and thought he might have died some 500 years ago.
Not only that, we top up our carbon-14 levels every time we eat.
Spindler and other scientists deduced that his body and belongings had been preserved in the ice until a fall of dust from the Sahara and an unusually warm spell combined to melt the ice, exposing the mans head, back and shoulders.
Another two days later (on 23 September 1991) the body was recovered from the ice by Rainer Henn from the Institute of Forensic Medicine at the University of Innsbruck, and was flown to his institute by helicopter.
Next day, when Konrad Spindler from the Institute of Pre-and Protohistory of the University of Innsbruck saw the unusual pieces of equipment found together with the body (in particluar an ax with a bronze-like blade), he estimated a very old age (~4000 years) of the find.
Radiocarbon dating is used to work out the age of things that died up to 50,000 years ago. As far as working out the age of long-dead things goes, carbon has got a few things going for it. The proteins, carbohydrates and fats that make up much of our tissues are all based on carbon.
Everything from the fibres in the Shroud of Turin to Otzi the Iceman has had their birthday determined the carbon-14 way. There's plenty of hydrogen, oxygen and nitrogen in living things too, but carbon's got something none of them do — a radioactive isotope that can take thousands of years to decay.