Because of its continental climate, temperatures in Fez are rather extreme -- especially during summer. Winters are cold, spring and autumn are warm, and summers are very hot. If you can, do not come here during July and August, when temperatures can reach the 45 Celsius degrees (120 F).
In the picture you can see one of the signs that mark one of the tourist routes. This is the pink circuit. The white arrow above marks the direction of the circuit. Look for these signs when walking in the medina of Fez in order not to get lost.