Death from Hydrocution results due to the contact of skin with:-

Immersion syndrome (Hydrocution/submersion inhibition/cold water drowning): It refers to syncope resulting from cardiac dysrhythymias on sudden contact with water that is atleast 5degC lower than body temperature Mechanism: Vagal stimulation leading to asystolic cardiac arrest ('diving reflex'), or ventricular fibrillation secondary to QT prolongation after a massive release of catecholamine on contact with cold water. The resultant loss of consciousness leads to secondary drowning.