Coronaviruses are a family of so-called “
enveloped viruses”. This means they are
coated in an oily coat, known as a lipid bilayer, studded with proteins that stick out like spikes of a crown, helping to give them their name – corona is Latin for crown.
Research on other enveloped viruses suggests that this oily coat makes the viruses more susceptible to heat than those that do not have one. In colder conditions, the oily coat hardens into a rubber-like state, much like fat from cooked meat will harden as it cools, to protect the virus for longer when it is outside the body. Most enveloped
viruses tend to show strong seasonality as a result of this.
Research has already shown that Sars-Cov-2 can survive for up to
72 hours on hard surfaces like plastic and stainless steel at temperatures of between 21-23C (70-73F) and in relative humidity of 40%. Exactly how the Covid-19 virus behaves at other temperatures and humidity has still to be tested, but research on other coronaviruses suggests they can
survive for more than 28 days at 4C. (
Read more about how long Covid-19 can survive on surfaces.)