A device control device for controlling an on-vehicle device based on a vital sign of a user, the device control device including: a vital sign measurement unit (101) configured to measure, in time series, the vital sign of the user； a parameter extraction unit (102) configured to extract time-series parameter values for evaluating current statuses of the user based on the vital sign measured continuously by the vital sign measurement unit (101)； a determination unit (120) configured to determine whether a factor of a change in the vital sign is a change in a health condition of the user or a change in an environment temperature around the user, based on the parameter values extracted by the parameter extraction unit； and a control unit (130) configured to control the on-vehicle device based on a result of the determination made by the determination unit (120).
