To answer that, we have to elaborate a bit: why do you measure your temperature at all?

The hormone released after ovulation – progesterone – causes your body temperature to rise. When the temperature has gone up, we know: you ovulated!

However, it is not enough to take the temperature only once, because the mere level of the temperature does not tell us how high the progesterone is.

→ That's why we need a temperature curve!

To determine an undisturbed temperature curve, we need the temperature at rest: the basal body temperature. A temperature that is very close to the basal body temperature is the waking temperature. This is the temperature that you measure directly after waking up. In the past, there was no way to measure the actual basal body temperature, so people took the waking temperature and tried to measure it at the same time every day if possible. 

So the actual basal body temperature can actually only be measured when you are completely at rest - that is, when you are asleep. That is exactly what trackle does! trackle measures while you sleep and can thus determine the actual basal body temperature.

How does it work?

You wear trackle while you sleep. trackle measures your core body temperature every minute. The phases in which trackle acclimatises are the warm-up and cool-down phases. These are taken out of the calculation of the basal value.

We have produced a short video to explain this: