Real accounts of your rectal temperature experiences.. VoyUser Login ] Not required to post. Post a new public message: * HTML allowed in marked fields. 2-20. WHEN SHOULD I TAKE A RECTAL TEMPERATURE ? a. A rectal temperature should be taken if one of the two following situations exists. (1) The physician or nurse. The body is made up of many, many millions of cells which you can not see unless you use a microscope. Special cells come together to make an organ.