请问状语从句?Any specific reason I should know about in case peopl

请问状语从句?Any specific reason I should know about in case people ask where you are
Any specific reason I should know about in case people ask where you are．

请问这句句子中,in case people ask where you are. 是以 in case　引导的状语从句吗?in case ＝if的意思吗?