It means the garment should not be tumble dried. A low-temperature or short programme does not override that care instruction.
Understanding this situation
The fabric, coating, trim or construction may be unsuitable for the combination of movement and heat. The appliance cannot identify that restriction automatically merely because it offers a delicate setting.
A useful next step
Use the alternative drying method specified on the label. Keep restricted items out of mixed dryer loads before starting. If an item is damaged after unsuitable drying, retain its care information and selected programme rather than assuming the dryer must have overheated.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.