Stroke risk rises as mercury falls

THE risk of stroke doubles when the mercury drops to zero, Australian research shows.

In a first-of-its-kind study, researchers from the George Institute for Global Health in Sydney have measured the effect of low ambient temperatures in triggering stroke, and have found that risk starts to creep up once the temperature falls below 20°.

The post-hoc analysis of 2000 medical records from a randomised trial of intensive blood pressure lowering among patients with intracerebral haemorrhage found that almost 80% of strokes occurred below this temperature.

At about 10°, the