As temperature rises, the number of photons increases and with it the photons will collide. When the temperature rises, the resistance increases. For some materials, resistivity or ohmic resistance is a linear function of temperature. The resistivity of a conductor rises with temperature. Resistivity and conductivity are reciprocals. The scattering of electrons determines ohmic resistance. The more the dispersion, the higher the resistance.
Resistivity increases within increasing temperature in conductors and decreases with increasing temperature in insulators. The temperature dependence of resistivity can only be understood with a quantum mechanics. The deflection or scattering of electrons with phonos is a source of resistance. When the temperature goes up resistance goes up.