Shaykh Ibn Bāz mentions three types of khawf (fear) in his explanation of Thalāthat-ul-Uṣūl:

[1] Khawf al-Sirr (Secret (Supernatural) Fear)

[2] Khawf al-Asbāb al-Ḥissiyyah (Fear of Tangible Means)

[3] al-Khawf al-Ṭabīʿī (Natural Fear)

He defines the first as:

The second type of fear is the fear of something which is tangible and realistic such as the fear one has of an enemy. The devil, for instance, tries to cause the believers to fear his allies but Allāh has ordered us to ignore these flimsy attempts and to fear Him alone:

Natural fear is the fear which Allāh has put in us as a part of our nature. This includes, for instance, the fear of venomous creatures, predatory animals, criminals, murderers, the fear of hunger, thirst, cold weather etc. Taking precautions against these fears is not blameworthy.

Blameworthy fear is the fear which stops one from fulfilling an obligation towards Allāh.