Good morning, First Minister. You mentioned the aerosol-generating procedures. My understanding is that, going forward, Welsh Government are promoting a one-hour gap between those procedures to allow air exchange in surgeries, but the science behind this is negligible. Europe looked at 15 minutes between aerosol-generating procedures, but they've since dropped that because the science is so non-existent on that particular process. On a day like today, when it's very still, hot and muggy, how do you—? First of all, where is the science for that, First Minister? Where can I go and reference that? And secondly, how do you actually propose that dentists are able to implement that change of air, that air exchange, for an hour? Because just opening the windows on a day like today simply wouldn't do it.