I do not see any unit for the temperature load. Should I specify it in Degree Centigrade or Degree Fahrenheit ?

The unit of temperature loading should be consistent with the value of ALPHA that is specified as part of the DEFINE MATERIAL command. If your base unit setting is Metric, then the material properties including ALPHA would be in metric units ( so ALPHA would be in /deg C). In that case you would define the temperature rise/fall in degree Centigrade units. Otherwise if your base unit setting is English, then the material properties including ALPHA would be in English units ( so ALPHA would be in /deg F). In that case you would define the temperature rise/fall in degree Fahrenheit units. So you need to check the Base Unit Setting and the Alpha value defined in your file and then specify the temperature loading accordingly.