US endures deadly heat wave

On Sunday 30th June, residents of the town of Yarnell in Arizona were ordered to leave their homes due to a nearby wildfire. The fire started a couple of days earlier and was spreading fast due to drought conditions caused by a severe heat wave. While the town’s residents all managed to escape the approaching flames, those tasked with halting its advance were less fortunate. On 1st July, 19 members of a specialist firefighting unit called the Granite Mountain Hotshots were killed whilst tackling the blaze, making this the deadliest US wildfire since 1933.

Wildfires are a relatively common occurrence in hot, dry climates, and can start in various ways, both natural (such as volcanic eruptions) and man-made (for example, dropped cigarettes or even deliberate arson). In the case of the fire at Yarnell, a bolt of lightning supplied the ignition. This quickly developed into a vast inferno, spread by strong winds and exacerbated by the large-scale heat wave affecting Arizona. The unusually high temperatures meant that surrounding vegetation was extremely dry, providing the fire with an extensive source of highly flammable fuel.

Fires aren’t the only hazards of a heat wave such as this. In the state capital of Phoenix, flights were cancelled as temperatures exceeded the approved upper limit at which planes can operate safely. All across the region, officials issued warnings encouraging residents and visitors to seek shade wherever possible, and combat the effects of dehydration by drinking lots of water. Children and the elderly are particularly at risk, and already dozens of people have sought medical treatment for heat-related health problems. Arizona isn’t the only afflicted state: in Las Vegas, Nevada, temperatures recently equalled the highest ever recorded for the city, while in Death Valley National Park, California, the mercury climbed higher still, to over 53 degrees Celsius.

In a statement, President Barack Obama hailed the Granite Mountain Hotshots as “heroes” who “selflessly put themselves in harm’s way to protect the lives and property of fellow citizens they would never meet” – sentiments echoed by state governor Jan Brewer, who described it as “a truly unimaginable loss” and “as dark a day as I can remember”. Meanwhile, the fire still rages, with over 250 firefighters continuing to battle its spread, helping to ensure it cannot claim any more lives.