After complaints on heat and humidity under closed retractable roof on Friday, UEFA decided not to use this feature any more, unless unexpected weather conditions force them to.
As we already wrote, Poland-Greece game was the largest Euro game and 2nd largest tournament game ever to be played under a closed roof. Decision to use the retractable membrane was made by UEFA due to alarming weather forecast which indeed led to massive rainfall before the match. And since Friday was also opening ceremony day, retractable roof was used as precaution.
However closing it disabled air circulation and caused heat compared by Polish coach Franciszek Smuda to a sauna. Many fans and journalists also complained that since Friday was a very warm day apart from the storm, temperature inside was rising fast.
Previously rumors had it that all group games played at Stadion Narodowy would have the roof closed, but now UEFA declines such a decision was made. Robert Faulkner, a spokesman for the federation, announced:
The roof will not be used during upcoming games unless exceptional circumstances occur.