It's only dangerous because you are paranoid. :rasta:

It doesn't raise your blood pressure that much. When I was hospitalized when I first got cancer, I had my blood pressure tested a couple hours before smoking a joint in the parking lot. Not much after, they tested me again. My blood pressure is around 110/50, I measured 121/57 after the session. Only a slight increase. Not dangerous unless your blood pressure was really high to begin with.