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While geographically-/geologically-distinct hot springs harbor different levels of microbial diversity, some of them encompass several such taxa which have no strain reported for laboratory growth at >45°C. We, therefore, hypothesized that native geomicrobial factors could be potent determinants of the microbial habitability of hot spring environments. To test this hypothesis, aquatic microbial communities were revealed 40 metataxonomically, and considered in the context of spring-water chemistry, along the 85-14°C hydrothermal gradient of a sulfur-boron spring named Lotus Pond located at 4,436 m, within the Puga geothermal area of the Indian Trans-Himalayan region of Ladakh. Water samples were studied from four distinct sites along Lotus Pond's spring-water transit from the vent to an adjacent river called Rulang. Insinuations obtained from geomicrobiological data were tested via pure-culture growth experiments in habitat-inspired media. Microbial 45 diversities were found to be high at all the sample-sites; majority of the genera identified at the 70-85°C sites were found to have no report of laboratory growth at >45°C; concurrently, these sample-sites had high concentrations of the kosmotropic solutes boron, lithium, sodium, sulfide, thiosulfate and sulfate, which are known to biophysically stabilize macromolecules. Based on the universal thermodynamic status of these solutes, we conjectured that they may be instrumental in helping mesophiles withstand high in situ 50 temperatures. Corroboratively, growth experiments with a mesophilic, 80°C-isolate, Paracoccus SMMA_5 showed that at 50°C and 70°C, depending on the incubation-time, lithium/boron/sulfate/sodium/glycinebetaine either increases the number of colony-forming units present in the culture or arrests decline of the same. Incubations at 70°C, followed by fluorescein diacetate staining and flow cytometry, showed that these solutes keep more cells under viable condition than in ready-to-divide state. We concluded that kosmotropes 55 and compatible solutes help mesophiles overcome the chaotropic effects of heat by augmenting such indigenous, entropy-minimizing biophysical mechanisms that apparently trade-off cell division for cell viability.