Wilderness
'Wilderness' signifies something with little life in it, as described in the internal sense in Luke 1:80 'Wilderness' signifies somewhere there is no good because there is no truth. 'Wilderness,' as in Jeremiah 23:10, signifies the Word when it is adulterated.
(Reference: Arcana Coelestia 1927)
Heat nor sun
In Isaiah 49:10, this signifies from the loves of falsity and from the love of evil. (Apocalypse Explained 386[27])