Close temperatures keeping characters from hiking round Thailand (5-4)
I believe the answer is:
tight-knit
'close' is the definition.
(tight-knit can mean close or intimate)
'temperatures keeping characters from hiking round thailand' is the wordplay.
'temperatures' becomes 'tt' (an abbreviation for temperature written twice).
'keeping' means one lot of letters goes inside another.
'characters from' is an anagram indicator (the same characters in a new order).
'round' indicates putting letters inside.
'thailand' becomes 'T' (abbreviation on car registration plates).
'hiking' with letters rearranged gives '[hiking]'.
'tt' placed around '[hiking]' is 't[hiking]t'.
'tighknit' going around 't' is 'TIGHT-KNIT'.
(Other definitions for tight-knit that I've seen before include "Well organised in concise way - using wool?" , "Meshed" , "Closely bound" , "Strongly bound together" , "'intimate'" .)