One drilling method embodiment includes: obtaining a set of drilling parameters, possibly from a drilling plan; applying the set of drilling parameters to a physics-based model to obtain an estimated log of a downhole parameter such as temperature; and refining the estimated log using a data-driven model with a set of exogenous parameters. Temperature cycling and cumulative fatigue (or other measures of failure probability or remaining tool life) may be derived to predict tool failures, identify root causes of poor drilling performance, and determine corrective actions.