I found this article very helpful but 5 days too late! Some of which I had already done to keep our little girl and 2 dogs as well as myself cool in the heatwave we’ve just had in the UK.
Besides being drained of energy and too hot to play outside for long periods of time in the sun. We made do with our sun tent up in the garden to shade the paddling pool which we all enjoyed playing and cooling off in.
Ice lollies and anything cold and refreshing as well as lots of sunscreen and sun hats helped to keep cool in the hot weather.
Keeping blinds closed and open only a quarter of the way to allow any breeze to circulate through and the sun out and a fan going to help circulate and cool breeze.
Baby in just a nappy to sleep with just a sheet on the mattress. No waterproof covers which seem to make baby sweat. Bamboo sheets are amazing so sleep under if baby is too young to sleep with just a nappy.
Frozen water bottles in front of the fan to cool the air in the room are all a great help.