An implantable medical device (IMD) automatically determines at least a portion of the parameters and, in some instances all of the parameters, of an exposure operating mode based on stored information regarding sensed physiological events or therapy provided over a predetermined period of time. The IMD may configure itself to operate in accordance with the automatically determined parameters of the exposure operating mode in response to detecting a disruptive energy field. Alternatively, the IMD may provide the automatically determined parameters of the exposure operating mode to a physician as suggested or recommended parameters for the exposure operating mode. In other instances, the automatically determined parameters may be compared to parameters received manually via telemetry and, if differences exist or occur, a physician or patient may be notified and/or the manual parameters may be overridden by the automatically determined parameters.