14 August

In the US, parents of pre-schoolers having a working bee to make Corsi-Rosenthal boxes to protect their kids from Covid. Corsi, an engineer and Rosenthal, a producer of air conditioning filters, designed these as a very low-cost way to filter air. It’s just a box fan with some air con filters taped to it. These are extremely effective at cleaning air, and cost less than $100 to make. That schools don’t already have these is criminal neglect, in some countries students make them in class as a school project.