Well mandm13, warm is a relative term...

The fire coming off of it is a normal gas (or liquid propane) flame, and the size of the underwater manifold also determines the BTU output (usually between 30,000 and 90,000 BTU/hr). As for the water, that really depends on the volume of the bowl, reflecting pool, or fountain that the manifold is installed in. The greater the volume of water in proportion to the fire manifold, the cooler the water will stay. It should be noted though, that even if you leave the fire-on-water manifold burning all night, the water won't warm up significantly -- open air cools the water, and the heat from the flames mostly rises leaving the water safe to touch.

If you want to find out more information, follow this link to visit our website:

https://www.cjshearthandhome.com/outdoor-living/fire-on-water/fire-on-water-features