Agua Caliente means hot water in Spanish, and is the name of the tiny community near the spring.
Apparently I visited it on the wrong day, mid February 2005.

The spring, according to locals, had been "
tapada" , stuffed up, so they had just dug it out,
which explains the muddiness of the water. I daringly stuck my foot in and felt the spring bubbling,
but not hot, just luke warm. Time to change the place name to
Agua Tibia.

In the past, according to locals, the spring had been much more active, and had been the usual
subject of a
proyecto to develop it as a health spa? This is not a joke.

I´ll visit again in a few months to see if it cleared up.
Nope, it's still mucky (6/06), because the cattle keep trampling through it.
That´s what´s left to the public  of Coyame´s mineral spring
Type:  hamlet
Municipio: Catemaco, Veracruz
Location: near Sontecomapan
Population: 20
Economic Activity: cattle
Claim to fame:  hot water spring
Tourism: 0
Access: manageable terraceria from Sontecomapan to Coxcoapan
Villages of Laguna de Sontecomapan, Catemaco, Veracruz

Agua Caliente