COVID is an airborne disease, of course, and we know good ventilation and air purification are very effective in combating infection. Is there more, First Minister, we could be doing on this front? Belgium has installed carbon dioxide monitors in schools and, indeed, workplaces to see if ventilation needs to be improved. Ireland this week has announced a further €60 million investment in air purification devices in schools, using a mixture of high-efficiency particulate air and ultraviolet light. Given the estimated 3,500 children who continue to suffer the symptoms of long COVID in Wales, isn't this an investment in our children's health, as well as everyone else's, that we should also be making?