This day is mostly about stamina. You’ll be walking for almost 8 hours, and the hard part isn’t the climb but the descent. You start high up, in Guarda, and spend the rest of the day mostly heading downhill.
That sounds kind, until your knees start to disagree after a few hours. Descending well over 1100 metres is a lot. Take short steps, use poles if you have them, and rest more often than you think you need to.
The morning is still chilly, as the highest point of the stage comes just after you set off. After that you settle into your rhythm, until Celorico da Beira comes into view. Start early, so you arrive in daylight and don’t have to rush.