On the MAQS label it recommends the daytime high be higher than 10C to treat, and I'd assume that means throughout the course of the treatment. I'm also pretty sure it says not to feed while using MAQS, although you can have a honey super on, and you should if the bees have no food. MAQS is safe to use with supers on, although I'm a little uncomfortable with it, so I don't use that honey for human consumption just to be safe. NOD Apiary, the company that makes MAQS and FormicPro, has lots of great info in their FAQ sections for how and when to treat properly.