Some viruses and bacteria can survive freezing for thousands of years. Permafrost (ground with a temperature of or below 0°C for at least two consecutive years) covers 25% of the Northern Hemisphere. Whilst permafrost has persisted for millions of years, it is now thawing rapidly because of global warming. When permafrost thaws, microorganisms that were previously dormant can be released and become active. Some microorganisms may be pathogens, which can infect and potentially cause severe disease in humans, animals, and plants with major impacts on public health, socioeconomic wellbeing, and natural ecosystems. Global warming and increased disturbance of permafrost from human activities in the Arctic Circle are raising the likelihood of future localised outbreaks, or even pandemics, from dormant pathogens hidden in these frozen soils. This article provides a background to the risks associated with the release of pathogens from permafrost, how these risks can be minimised, and the implications for policy and international cooperation in light of the Covid-19 pandemic.