Trigger entails/necessarily involves Fire. Fire is the opposite of Cold. Cold is related to Degree. Degree is related to Single. 
Physician is related to People. People can be used for Work. Work is related to Practice. Practice is a synonym of Pattern. 
Trigger --Entails--> Fire <--Antonym--> Cold <--RelatedTo--> Degree <--RelatedTo--> Single 
Physician <--RelatedTo--> People --UsedFor--> Work <--RelatedTo--> Practice <--Synonym--> Pattern 