Refreshed squaddies slept outside (8)
I believe the answer is:
restored
'refreshed' is the definition.
(restore can mean to refresh or fix)
'squaddies slept outside' is the wordplay.
'squaddies' becomes 'or' (abbreviation for Other Ranks in the military).
'slept' becomes 'rested' (sleep is a type of rest).
'outside' indicates putting letters inside.
'or' inserted into 'rested' is 'RESTORED'.
(Other definitions for restored that I've seen before include "Returned to original condition or place" , "Brought back to original condition" , "Returned to former state" , "mended?" , "King Charles was" .)