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The temperature dependence of the 'generalized' Wien displacement law for tantalum and luminous-flames has been investigated. It is shown that the emitted thermal radiation of tantalum belongs to the same universality class as that of tungsten and zirconium and titanium carbides. The emitted thermal radiation of luminous flames belongs to the universality class as that of a black body. The true temperatures of investigated matter are defined.

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In this work, attention is mainly focused on those properties of water which are essentially changed in the physiological temperature range of warm-blooded organisms. Studying in detail the half-width of the diffusion peak in the quasi-elastic incoherent neutron scattering, the behavior of the entropy and the kinematic shear viscosity, it is shown that the character of the translational and rotational thermal motions in water radically change near TH ~ 315 K, which can be interpreted as the temperature of the smeared dynamic phase transition. These results for bulk pure water are completed by the analysis of the isothermic compressibility and the NMR-spectra for water-glycerol solutions. It was noted that the non-monotone temperature dependence of the isothermic compressibility (βT) takes also place for the water-glycerol solutions until the concentration of glycerol does not exceed 30 mol%. At that, the minimum of βT shifts at left when the concentration increases. All these facts give us some reasons to assume that the properties of the intracellular and extracellular fluids are close to ones for pure water. Namely therefore, we suppose that the upper temperature limit for the life of warm-blooded organisms [TD = (315 ± 3) K] is tightly connected with the temperature of the dynamic phase transition in water. This supposition is equivalent to the assertion that the denaturation of proteins at T ≥ TH is mainly provoked by the rebuilding of the H-bond network in the intracellular and extracellular fluids, which takes place at T ≥ TH. A question why the heavy water cannot be a matrix for the intracellular and extracellular fluids is considered. The lower physiological pH limit for the life of warm-blooded organisms is discussed.

The optimal temperature for the human life activity has been determined, by assuming that this parameter corresponds to the most intensive oxygen transport in arteries and the most intensive chemical reactions in the cells. The oxygen transport is found to be mainly governed by the blood saturation with oxygen and the blood plasma viscosity, with the both parameters depending on the temperature and the acid-base balance in blood. Additional parameters affecting the erythrocyte volume and, accordingly, the temperature of the most intensive oxygen transport are also taken into account. Erythrocytes are assumed to affect the shear viscosity of blood in the same way, as impurity particles change the suspension viscosity. It is shown that theoptimal temperature equals 36.6 ∘C under normal environmental conditions. The dependence of the optimal temperature for the human life activity on the acid-base index is discussed.

The true temperature of thermal radiation of molybdenum and luminous flames is defined from the temperature dependences of generalized Wien's displacement and Stefan-Boltzmann's laws. For determining the true temperature of molybdenum, experimental values of either the position of the maximum of the spectral emitted density or the total emitted density are needed. It is shown that the thermal radiation of molybdenum belongs to the same universality class as that of tantalum, tungsten, and zirconium and titanium carbides. The thermodynamic functions of thermal radiation of molybdenum and luminous flames are constructed.