Methods and systems for activity monitoring include capturing an infrared image of an environment that comprises at least one patient being monitored and at least one infrared-emitting tag. A relationship between the patient being monitored and the at least one infrared-emitting tag is determined. An activity conducted by the patient being monitored is determined based on the relationship between the patient being monitored and the at least one infrared-emitting tag. A course of treatment for the patient being monitored is adjusted based on the determined activity.