My smartwatch kept failing in the cold – here’s how I fixed heart rate and GPS accuracy

A man running in the winter.

The first time it happened, I assumed it was a one-off. I stepped out into the winter cold, something we know all too well in England, tapped Start on my run, and my smartwatch immediately lost the plot.

My apparent heart rate spiked when I was barely moving, then flatlined, then snapped back to something believable.