Mattia Debertolis, who lived in Stockholm and competed for IFK Lidingö, was found unconscious during the middle distance race in the World Games on Friday.
Debertolis was taken to hospital, but his life could not be saved.
The cause of death is not known, but Harald Bauer says that "it was 32 degrees hot and very high humidity" during the competition.
So it felt like 40 degrees. He apparently got heat collapse and lay in the forest for an hour I've seen. He was then affected by oxygen deficiency and his organs stopped working, says Harald Bauer.
The Swedish national team traveled with the same bus as Debertolis to the competition.
"It's incredibly tragic that we have lost a fine orienteering friend. We talked to Mattia before the middle distance and now this morning we were met with the message that he is no longer with us. It feels unfathomable", says national team manager Håkan Carlsson in a statement to TT.
"One of our very best"
Debertolis competed for the Italian national team and participated in several World Championships and the World Cup. Debertolis has competed internationally since 2014 and was ranked 135 in the world.
He was resident in Stockholm where he studied at the Royal Institute of Technology and was also active in IFK Lidingö.
I think he has run for us for at least five years. He was one of our very best elite runners and has run the three major events Tiomila, Femdagars and Jukolakavlen in our club colors, says Harald Bauer.
"Honor his memory"
"I cannot describe in words the unfathomable grief over this tragic loss. Our thoughts go to all who mourn Mattia. I urge the global orienteering community to honor his memory", says the President of the International Orienteering Federation Tom Hollowell in a statement.
World Games are held every four years and are for sports that are not included in the Olympic Games program.
