APA (edition "APA 6") Psychology and Education

assessing stress for an experiment

i need a few simple methods to assess stress in an experiment.
self-reported stress measures.
for example one of the known self-reported stress test is the (perceived stress scale PSS) but this scale only assesses the participant’s current stress level given his past.
what I am looking for is a method to assess stress after I do an experiment ( a 7:00 min task that may increase this stress and frustration of the subject)
can I simply as him to rate his frustration level and stress level?
the stress scale should indicate if my task increased his stress level.
please find an answer to this question with references from google scholar.