I travel every day between Maarssen and Amsterdam Centraal. If outside is cool and rainy and also windy the trains have air conditioning on. Now that there are several hot days the air conditioning is not working. People travel with these trains sometimes for more than 30 minutes in temperatures as high as over 40 Celsius. Ignoring the fact that these trains have no toilette on board, it is unacceptable for people to ride in a sauna and some of them to get sick and faint or vomit because of the unbelievable high temperature and the lack of air in the train. Opening some very small windows is not helping at all. We are paying customers and we deserve to be offered the same conditions like people who travel with the intercity.
It is very seldom for me to be happy with NS. If I have 3 days in a row without delays, trains being cancelled and similar I think miracles exist. I had situations when I could go as far as Utrecht to find out there was no train available for Maarssen. I spend 50 minutes by bus from Utrecht to Maarssen while the train ride is 9 minutes (provided the train is running). Everything is wrong with NS services beginning with respecting their own schedule, their app not showing up to date info and the wrong information and the chaos in big stations when somethings happens. They cannot control anything.