All the cards state they should be discarded at the end of your turn. Does this mean end of your turn during the investigator phase or mythos phase? If it means investigator phase then the conditions are gone before any monsters could attack you, making it easier to fight them off.
If you have a look at page 24 of the RR I think it should be clear that the term "turn" means the Investigators turn during the Investigator Phase.
A game of Mansions of Madness is played over a series of rounds. Each round consists of two phases, the investigator phase and the mythos phase.
During the investigator phase, the investigators each take one turn
in the order of their choice. During an investigator’s turn, that
investigator performs up to two actions.