Yes, if it is found in plain sight, while performing duties in a place they are required to be to perform their job. However, they are not required to report it.
Generally speaking, government agents need a warrant to search a residence. However, firefighters do not need to obtain a warrant before entering a building to fight a fire. Once in the building, firefighters and officials can remain there for a reasonable time to investigate the cause of the fire and they can seize any evidence that is in plain view. Additionally, emergency medical services, like paramedics, do not need a search warrant to enter a building to provide medical assistance. However, you are allowed to refuse their assistance; whereas, you cannot turn down the fire department.
For example, a search inside a wooden box which contained marijuana was legal because the firefighter was investigating a hotspot after a fire, and saw electrical cords leading from the hotspot to the box. In the alternative, marijuana found when firefighters opened up a basement freezer to satisfy their ‘curiosity,’ was not allowed to be seized. See State v. Voss, 683 N.W.2d 846 (Minn. Ct. App. 2004).