Wiltshire Air Ambulance landed in Malmesbury after a man suffered a cardiac arrest.
Emergency services were called to the scene in High Street at around 2.30pm this afternoon following reports of a male collapsing near to the bridge.
Two passersby provided emergency first aid until 999 crews arrived at the incident.
The green and yellow critical care helicopter landed in St. Aldhelm Mead at 2.45pm.
The casualty, a man from Chippenham, was taken to Great Western Hospital – landing at 3.45pm. His condition is currently unknown.