Temperature is a critical parameter that significantly influences the performance, lifespan, and safety of lithium-ion batteries. It influences electrochemical reaction kinetics, internal resistance, and lithium inventory, which together determine capacity degradation, cycling efficiency, and state of health. High operating temperatures accelerate degradation by promoting the formation of undesirable byproducts, damaging electrode materials, and increasing the risk of thermal runaway. This paper presents a comprehensive review of LIB behavior under high-temperature conditions, focusing on automotive applications. It investigates the thermal characteristics, degradation mechanisms, and effectiveness of various thermal management strategies. The study distinguishes between hot and cold climatic conditions and examines temperature-induced capacity fade, cyclic degradation, and accelerated calendar aging. It also discusses the implications of high-temperature fast charging, considering both short-term and long-term impacts. Furthermore, temperature-based assessments and comparisons are performed at both the cell and pack levels for different lithium-ion chemistries. The aim is to provide a technical evaluation of the long-term viability of electric vehicles operating in hot and desert climates, to identify existing research gaps, and to highlight emerging directions in high-temperature battery technology.