I think getting fresh air at the dog park is also something reasonable to do if you are feeling sick. I also used to think I couldn’t do anything if o called in sick off work but now I realise that there is a difference between the energy required to work for 8 hours and going to the dog park for one, or having a coffee or popping into the shop for supplies. Being able to do that doesn’t mean you are well e ough for a whole day of work.