Extreme heat may be crucial factor in human spread of bird flu

As heatwaves hit the US, dairy workers struggle to wear PPE. The country now faces its biggest human outbreak

Extreme heat may be a crucial factor behind the biggest bird flu outbreak in humans in the US as officials continue to track the virus’ spread.

A heatwave in Colorado likely caused personal protective equipment not to work correctly for workers culling poultry infected with H5N1, a highly pathogenic bird flu. Four people have tested positive for H5N1 and a fifth is also expected to have their case confirmed as bird flu, officials said this week.