Extreme heat is now one of the defining public health challenges of a warming world, explains Prof IAN WILLIAMS
IN MY quarter of a century writing for and editing Britain’s biggest-circulation outdoor magazine, I became very familiar with Lyme disease.
Once a year, in spring, just as the bracken started to uncurl its most beautiful fiddleheads, I would remind our half a million readers about the dangers of this nasty, sometimes fatal, tick-spread disease.
Over those 25 years the incidence of Lyme disease seemed to get bigger every year but nobody knew why or even if this was because people like me were simply making country walkers more aware of the risks and symptoms.
Extreme heat is now one of the defining public health challenges of a warming world, explains Prof IAN WILLIAMS
New research into mutations in sperm helps us better understand why they occur, while debunking a few myths in the process, write ROX MIDDLETON, LIAM SHAW and MIRIAM GAUNTLETT


