Use 'foxhole' to describe a soldier's protective hole during battle, not a structure like a bunker or base. Amidst heavy shelling, they took cover in their foxholes.
Pro Tip 2/3
Temporary Shelter
'Foxhole' refers to a small, temporary shelter, unlike permanent military fortifications. After advancing, soldiers had to dig new foxholes each evening.
Pro Tip 3/3
Immediacy
'Foxhole' often implies quick action; soldiers dig them urgently for immediate protection. The platoon scrambled to dig foxholes under the threat of an imminent attack.