Sauna temperatures are between 140°F and 220°F (or 60-110°C). 140 is very low, almost cold. 220 or so is about the max.
Now with little kids we usually heat ours to 140 , but I would prefer 180. Public saunas (like in the swimming halls etc.) Are typically set to 180-200°F.
Heat is nice, but even nicer is the heat/steam waves that come from throwing "löyly" (water to stones).