They mean about the same but to say that you have a temperature really means that your body has a certain amount of heat. A person who has a temperature of 91 degrees does not have a fever but does have a measurable temperature - they are not dead.
People usuallly say that they have a temperture when they really mean that they have a fever.
A dead person certainly does have a temperature. This is one of the main determinants of time of death. Assuming a normal 37 deg. C. at death, a body loses roughly 1 deg. C. per hour until it reaches the ambient environmental temperature (in about 18-24 hours). After that time, it will tend towards whatever the ambient temperature happens to be.
In fact, everything hotter than zero degrees Kelvin has a temperature.