Sauna raises HR without increasing blood pressure though (modulo some possible initial short spike at the beginning), because your blood vessels dilate.
Cannabis causes dilation of blood vessels and elevated HR, it’s the same effect. If you take a big dab you can definitely feel your blood pressure drop and muscles relax even though your heart rate has increased.
Yeah it raises heart rate and blood pressure bc it dilates your blood vessels. The raised HR/BP are to counter that so you keep pushing the same amount of O2 per unit time.
That's one of the reasons. The primary reason is THC is a partial CB1 receptor agonist - CB1 is abundant in the central and peripheral nervous systems - so it increases sympathetic nervous system activity and norepinephrine, both of which raise heart rate independent of vasodilation.