We propose a workflow to validate parallel transmission (pTx) RF heating patterns using Proton-Resonance Frequency shift (PRF)-based MR thermometry. An agar+polyethylene powder cylindrical phantom, with similar dielectric properties to the human brain at 297.2 MHz, was designed to assess an 8-channel dipole array. RF heating was evaluated and compared between PRF-based MR thermometry, fibre optic probe measurement, and thermal simulation. The PRF reconstruction procedure was optimized to reduce artefacts. Given the importance of RF safety in pTx applications, this method enables accurate validation of RF heating simulations with minimal additional hardware requirements.