I am currently surface walking, looking at surface features and possible new sites to explore when I feel safe enough. Though it has never happened yet, I would not want to involve rescue teams in a Covid Secure rescue to get me out of trouble.
The limited volume of air in some spaces, coupled with heavy breathing would likely increase the virus count if someone was shedding. Hard surfaces, cool temperatures, high humidity and lack of UV light all seem to allow the virus to survive longer in the environment.
As age is a major risk factor in becoming very unwell and even not making it the fact that I should get my state pension this year is also in my mix of risk analysis.
Remote sites mid week should involve less meetings with others, but you never know who you might bump into!
It won’t be me underground for a little while yet.