Hourly ground temperature measurements from the highest shallow ground temperature monitoring system on Earth and sedimentological data were used to construct a thermal model at the Ojos del Salado, in the Dry Andes (5830 m a.s.l.). The results were used to investigate daily temperature fluctuations and the phase changes of water in the regolith, where the permafrost and ground ice are present. Model results reveal that the thermal evolution of the ground and the speed of phase changes are determined by the differing thermal properties of liquid and solid water, and change in their vertical distribution over time. At the start of summer, the increasing ratio of liquid water near the surface insulates deeper layers, and thus, melting is delayed and daily temperature fluctuations are damped in the regolith. The approach of the present study includes testing how simple, relatively low processing power required data analysis might be applied for Mars in the future. Periglacial and aeolian landforms were also surveyed, with a focus on thermo- and cryokarstic features, as previous studies have shown that patterned ground structures are rare in the region due to the highly porous nature of the dry regolith. Besides the wealth of aeolian features, gravel mantled megaripples, solifluction lobes, and thermo- and cryokarstic depressions, were found. In the case of the former, a close association with ephemeral ponds-hosting extremophilic microorganisms-was found, highlighting the fact that meltwater percolates horizontally even in this extremely dry environment. The thermo- and cryokarstic depressions also reveal the role of melting and its intricate connection to sublimation. As these features indicate degrading permafrost, closer investigation may provide useful analogs for earlier and contemporary climatic changes on Mars.