Kersee has designed Felix's training to improve her burst out of the starting blocks, her conditioning and her top-end speed.

WSJ: Allyson Felix's Olympic Hedge

It can end up in artificial water supply systems, including air conditioning systems, water services and cooling towers.

BBC: Legionnaires' Disease bacteria

Though the posher hotels had swimming pools, golf courses and nightclubs, this was a magnet for Jews of all classes, and many families and their friends returned to the same hotels or rooming houses year after year, until air conditioning, affluence and cheap air travel made alternatives available and brought the enchanted little world to an end.

ECONOMIST: Lexington