If someone dies from acute heroin intoxication, is it considered an illegal act?
In this country, taking or using heroin is illegal--it is crime, for which one could go to jail. If a policy has an exclusion for deaths occuring during an illegal act, that exclusion would allow the insurer to refuse payment, UNLESS it could be shown that the victim was drugged against his/her will. (E.g. someone assaulted or murdered him/her by holding him/her down and forcibly shooting him/her up; or the victim is, say, a diabetic, and someone replaced his/her insulin with heroin.)