Grand Prismatic Spring
The famous Yellowstone Park hydrotherm has a bathwater outer edge, between 30-40 Celsius
Frying Pan lake
Edge temperatures of the biggest hot spring in the world reach around 50 Celsius (86 – 104F).
Dominica’s World Heritage site has a flooded fumarole that can hit 92 Celcius (197.6 Farenheit) at its outer edge.