4PHRASE 不敢设想;想到…不寒而栗 If you say that you shudder to think what would happen in a particular situation, you mean that you expect it to be so bad that you do not really want to think about it. 不敢设想;想到…不寒而栗 [feelings]
I shudder to think what would have happened if he hadn't acted as quickly as he did.