Question & Answer

Can sunlight prevent or treat COVID-19?

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There are claims on social media that sunlight can prevent or even treat COVID-19. These claims have grown in Ireland, particularly with recent good weather.

  • The World Health Organization says that “Exposing yourself to the sun or to temperatures higher than 25C degrees DOES NOT prevent the coronavirus disease (COVID-19)”
  • COVID 19 has also been reported in countries that have hot and sunny weather.
  • Although some studies have suggested that temperature may influence transmission of the COVID-19 virus (how the virus spreads from one person to another), the evidence overall is inconclusive. COVID-19 virus transmission may have reduced as we experience warmer weather spells but we are also seeing the effects of public isolation policy, reduced migration and other preventative measures such as physical distancing and hand hygiene measures. It is far more likely that these measures are reducing the rate of transmission.
  • Although there are some health benefits, prolonged sun exposure can be dangerous.
  • When spending time in the sun, individuals should follow public health advice.
  • The current recommendations to prevent COVID 19 include: washing your hands well and often; covering your mouth and nose with a tissue or sleeve when coughing or sneezing and then safely throw away any used tissue where others will not touch it. Avoid touching eyes, nose and mouth with unwashed hands. Clean and disinfect frequently touched objects and surfaces. Avoid shaking hands or hugging when saying hello and greeting other people. Distance yourself at least 2 metres away from other people, especially those who might be unwell.

Things to Remember


  • Lead Researcher: Fiona Quirke, HRB-NEPTuNE, HRB-Trials Methodology Research Network, NUI Galway.
  • Reviewed by: Professor Declan Devane, School of Nursing and Midwifery, HRB-Trials Methodology Research Network, Evidence Synthesis Ireland & Cochrane Ireland, NUI Galway
  • Evidence Advisor: Dr. Maureen Kelly, College of Medicine, Nursing and Health Sciences NUI Galway
  • Evidence Advisor: Casey Donaghey, PPI Ignite, NUI Galway.
  • Journalist Advisor: Dr Claire O’Connell, Contributor, The Irish Times.