Template sensor - store previous attribute value in another attribute

[Troon]

See my solution to the similar question in this post:

Delayed or earlier sensor value

I can detect taking a shower by a steep rise in bathroom temperature. I want to switch on the floor heating to dry the room out afterward, but only if it was relatively cool beforehand. Is there a way to get the temperature value of e.g. ten minutes ago? If HA can’t do that I might construct a temperature sensor in Esphome to provide two values, temperature and earlier temperature.