The temperature rating of the sprinkler is indicated by the colors. The maximum ambient ceiling temperature and the occupancy classification must be taken into account when choosing the sprinkler with the appropriate temperature rating. Sprinklers are actuated by heat, so if the maximum ambient ceiling temperature isn’t taken into account, it could result in unintentional sprinkler activity. The frame arm, deflector, or coating material will typically have some color indicating the temperature rating if the sprinkler does not have a glass bulb.