When someone is in a manic episode and threaten to kill you, are they likely to act out the threat at that time?

See Below: We don't know what another person's verbalization might lead to, meaning will they act out on them or not. When threats like that are verbalized, they should be taken seriously -- get help for this person and get him/her evaluated by the professional. If you can't persuade the person to get help, you might dial 911 or bring this person to the nearest emergency room for an evaluation.

Threats to kill: That are specific & seem credible justify a call to 911. A person in a manic episode may act impulsively & make poor decisions. A credible threat to kill is an excessive reaction no matter what state of mind the person is in. An equally serious consequence to such a threat (involving the police), may increase the person's awareness of their threat & decrease the likelihood it will be repeated.