Low-temperature inductively coupled radio-frequency plasma is a key plasma source in semiconductor fabrication, wherein the neutral gas temperature (T_g) is one of the critical parameters influencing chemical reactions and plasma characteristics. Precise control of T_g significantly influences processes such as thin-film deposition and reactive ion etching, with its synergistic interaction with plasma parameters (n_e, T_e) often determining process outcomes. Consequently, a thorough understanding of the evolution of T_g and its correlation with discharge parameters has become a critical issue for optimizing semiconductor manufacturing processes. To achieve more accurate measurements of neutral gas temperature, this work employs three temperature measurement techniques: spectroscopy, Bragg grating, and fiber optic sensing. These methods are used to systematically investigate the variation patterns of neutral gas temperature (T_g) in nitrogen and nitrogen-argon mixed plasmas under different radio-frequency power, gas pressure, and gas composition conditions. To elucidate the gas heating mechanism, this work combines Langmuir probe measurements of electron density, electron temperature, electron energy probability distribution, with a global model simulations. The results show that when the RF power increases, the energy coupled to the plasma increases, the ionization reaction is enhanced, and the collision process and energy transfer between electrons and neutral particles increase, resulting in a monotonically increasing trend of T_g. When gas pressure increases initially, electron density and background gas density jointly rise, enhancing heating efficiency and driving rapid T_g growth. However, beyond 3 Pa, electron mean free path shortens and electron density declines. In contrast, background gas density continues increasing, leading to slower T_g growth.. In nitrogen/argon mixed system discharges, increasing the argon proportion significantly enhances the rate of T_g increase. This occurs because a higher argon ratio elevates the proportion of high-energy electrons and electron density, thereby strengthening ionization and neutral gas heating. Concurrently, argon metastable atoms enhance the density of excited nitrogen particles via the Penning process, promoting nitrogen molecular excitation to higher energy levels and further heating the gas. Additionally, we observe that the radial temperature distribution in pure nitrogen plasma shifts from parabolic to saddle-type with increased axial height, due to intensified electron collision excitation near the coil under electromagnetic field effects. The study also found that the glass transition temperature at the radial edge remained virtually unchanged with increasing atmospheric pressure. This is because, as pressure continues to rise, electrons beneath the coil struggle to migrate to the radial edge to collide with neutral particles, thereby limiting the heating of edge neutral particles.