Impossible to say without a lot of specific info. Factors like rider & bike weight, road pitch, ground speed, disc rotor type, disc pad type, presence or absence of cooling fins on pads a/o rotors and such will all affect the info.
Generally speaking, unless you are doing prolonged descending with brakes on hard and consistent, you won’t heat them excessively. Is there a specific question or concern you have besides that?
A useful technique to use in some cases of long braking, is to “cycle” the brakes with a relatively hard application to slow down, release the brakes for a moment to allow the pads and rotor to cool, and then reapply the brakes. Rinse & repeat down the hill. This can help cool the components a bit vs sustained loading.