One thing you might try is cooling your house or apartment overnight. I've noticed that most of my neighbors do not do this and I can't understand why! Fear of drafts and moving air perhaps?
Here is what I do and our apartment stays quite cool all day long! Granted our building is old and thick and insulated extremely well, but I do think that is the norm here in Switzerland.
1). After the sun has set and you're getting ready for bed, open all of the windows in the house with the LIGHTS OFF inside (unless you have screens).
2). With all the windows open, run a few fans and move the cooler evening air from outside IN.
3). If you prefer, switch off fans after 30 minutes or so. Otherwise, leave on all night with as many windows open as possible.*
*I tend to do steps 1 and 2 while I take a shower (also very cooling and refreshing at bedtime) in the bathroom with the door closed so that the light doesn't attract bugs through the open windows elsewhere in the apartment. If my husband wants to read, he will read in the spare bedroom with the windows closed.
FYI: With the lights off, we don't have trouble with bugs coming inside so we keep our bedroom window open all night long.
4). Go to sleep.
5). Wake up at 5 or 6 am FREEZING in your bed; reach for duvet. (This is only achieved by leaving the window open all night long.)
6). Get up at 6:30 or 7 am and CLOSE ALL WINDOWS and LOWER BLINDS or CURTAINS.
7). Leave house shut up like that until evening and then do it all again.
Works like a charm!! And it really means something coming from me: I'm 35 weeks pregnant in this heat!
I grew up in a high desert climate, so we could wait until 9 or even 10 am to shut up the house. But it's quite humid here, so it's already getting hot by 8 am. For best results, I recommend closing all the windows and drawing the drapes or blinds by 7 am to keep all the cool air locked inside. You can run one fan on low somewhere central in your apartment to circulate air throughout the day if you wish. But don't place the fan near a closed and covered window as heat still gathers there, particularly if the sun hits it, and you don't want to circulate that heat around your home.
Good luck! It's no fun being with a hot, grumpy baby.