Harsh terrain, extreme fatigue. Life as a wildland firefighter in a heatwave: ‘It’s not normal for humans’

Firefighters carry heavy packs along rugged slopes to calm fast-moving fires, and sweltering weather is compounding already dangerous work

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After 20 years fighting flames for the US Forest Service, the fire captain Abel Martinez has pretty much seen it all.

His lungs are scarred from the smouldering car tires and scorched homes that fed billowing flames alongside highways, through parched canyons, or over treetops in the Angeles national forest, the mountainous wilderness where he works in southern California. Whether it's a dry year or a wet one, the decades on the job have taught him that every fire season is likely to be a busy one.