Intelligent wearable devices integrating real-time health monitoring and on-demand treatment are obtaining widespread attention. However, precise monitoring and prolonged photothermal therapy of human bodies still face significant challenges. Herein, a phase change gel (PCG) with simultaneous strain sensing and photothermal therapy functions was fabricated using sodium sulfate decahydrate (SSD, Na2SO4·10H2O), polyacrylamide (PAM), and polydopamine-modified MXene (PDA@MXene). The PCGs possessed a suitable phase transition temperature and high enthalpy value (128.8 J/g), which provided sufficient thermal comfort. The PAM hydrogel effectively overcame the liquid leakage of SSD and achieved flexibility. PDA@MXene not only imparted the PCGs with excellent photothermal conversion efficiency (93.83 %), but also ensured strong adhesive properties to precisely monitor human motions. Interestingly, the PCGs exhibited temperature-sensitive adhesion ability by triggering the phase transition of SSD, thus obtaining high adhesion to the skin and painless detachment simultaneously. The temperature-induced adhesive PCGs exhibit great application prospects in portable medicine devices.