Recent multidisciplinary research on the lethal effects of the pyroclastic surges in the Vesuvius area showed that in the vicinity of Pompeii and Herculaneum, heat was the main cause of the death of people who had previously been thought to have died by ash suffocation. This study shows that exposure to the surges, measuring at least 250 °C (480 °F) even at a distance of 10 kilometres from the vent, was sufficient to cause the instant death of all residents, even if they were sheltered within buildings.