We are trying to conceive, so we chart my fertility days with basal body temperature readings. Every morning while I'm still in bed, my husband rolls me over on my tummy, pulls down my pj pants, and takes my rectal temperature with a basal thermometer, which once belonged to my mother. While he shaves, etc in the bathroom, i have to lie on my tummy with the thermometer in place. When he's done, he takes it out, writes down the rectal reading, and leaves it next to my chart. We also have one of my mom's mercury rectal thermometers, which was used on my 2 brothers, 2 sisters, and me. Now, my husband and I use for illness on each other, mostly for illness.