Stan is a rescue worker paramedic that works in the Joule Town area. A lightning bolt caused him to lose control over his vehicle and crash. He injured his leg and was able to temporarily fix it but he was unable to go anywhere. He managed to make it to a nearby cave to get out of the storm.
Ash Ketchum and his friends met
Stan when they also entered that cave to avoid the storm. He initially startled them but once they saw that he was injured and had introduced himself, he asked them to take the medicine to the town for the children waiting for it.
Ash Ketchum took the medicine and successfully delivered it for him while
Serena and the other rescued
Stan and took him to
Nurse Joy (Kalos) who determined he wasn't seriously injured.