Wet cloth doesn't keep in heat anyway, unlike sweaty plastic backings on sposies. PUL wraps/pockets are fine too as the laminate is breathable
My mum keeps telling me that cloth nappies will make DD too hot, but she doesn't get it
and she was shocked when she saw her wearing wool shorties in the hot weather, but if you were to wrap a tub of ice-cream in wool it would stay cool for longer as it is insulating, not just warm. There are eco companies now using wool as an insulator for frozen foods!