What i think is that you can not "observe" entangled particles. what you do, is that you measure them. when you find out the spin of an electron let's say, your are not finding it out, you are just making it be the way you "measured" it. its the Bell's therom if i I am not mistaken, check it...
what do you exactly mean by "photons at high temperature."
temperature is the kinetic energy of the molecules... you can not go faster than light, thus, you can not increase the temperature of photons!hope that helped