Basal Thermometers

Basal Thermometers

A simple way of determining the time of ovulation is by keeping a record of your early morning body temperature or Basal Body Temperature (BBT). BBT is the lowest temperature attained by the body during sleep. It is generally measured immediately after waking and before any physical activity, or eating or drinking has occurred.

In women, ovulation causes a slight drop in temperature at the time of ovulation, followed by an increases of 0.25 – 0.5°C in basal temperature. Since the difference is small, a specially calibrated ovulation thermometer should be used, which can detect these small differences.