On cloudy days, the Bureau of Environmental Quality simultaneously announces the one-hour PM2.5 concentration and the 24-hour PSI pollution index. Imagine that the smoke just drifts in, and the former reading increases, but the latter may still be in the "medium" range. How should people who go on a trip understand these two numbers?

On cloudy days, the Bureau of Environmental Quality simultaneously announces the one-hour PM2.5 concentration and the 24-hour PSI pollution index. Imagine that the smoke just drifts in, and the former reading increases, but the latter may still be in the "medium" range. How should people who go on a trip understand these two numbers?