Remote temperature sensing is highly demanded, especially in biological and medical applications where traditional contact thermometry is ineffective. Optical thermometry is a promising technique that provides high spatial, temporal, and temperature resolution. It can be used to monitor the temperature at the cellular level. The majority of optical thermal sensors known to date are based on the reading of a single luminescence parameter dependent on temperature, which limits their reliability and thermometric performance. The present study successfully implemented multiparametric temperature sensing using multiple linear regression, combining ratiometric and lifetime-based approaches. A series of water-soluble phosphorus(V) porphyrins was examined and compared in terms of sensitivity and resolution. These are complexes of phosphorus(V) with 5,10,15,20-tetraphenylporphyrin ([(TPP)P(OEt)2]+Br-, 1P), 5-(4-pyridyl)-10,15,20-triphenyl-porphyrin ([(MPyP)P(OEt)2]+ Br-, 2P), and 5,10-di(4-pyridyl)-15,20-diphenylporphyrin [(trans-DPyP)P(OEt)2]+ Br-, 3P). Multiparametric sensing demonstrated superior thermometric performance compared to single-parameter sensing, achieving thermal sensitivity Sr = 4.97% °C−1 and temperature precision δT = 0.06 °C in a (trans-DPyP)P(OEt)2 water solution. The subcellular distribution of porphyrins in the cytoplasm of living CHO-K1 and HeLa cells makes them promising agents for subcellular thermal sensing.