Piccard, Don. World Book Encyclopedia. USA: World Book, 1996. "1961, US Navy Officers Victor A. Prather, Jr and Malcolm Ross rose from a zero-pressure balloon at an altitude of 113,739.9 feet." 34,668 m The record setting flight in 1961 was a spectacular achievement, but a gas balloon was used, not a hot air balloon. Prather died at the end of the record-setting flight when they landed at sea. His flight suit filled with water and he drowned.
Even the achievements of these heroes don't count in this category, I think a salute to these space pioneers is in order anyway.
Lt. Cdr. Victor Prather and Cdr. Malcolm Ross in Gondola, May 4, 1961