I think that it is more complex than that. Latent heat is leaving a fermentation via evaporation with a blow-off tube affixed to a fermentation vessel (this phenomenon is easy to see because the vapor tends to condense in the blow-off tube). It is not a huge amount of heat, but it is a heat loss. Whenever a liquid makes the phase change to gas, it carries away heat. That is why water cannot get any hotter than 212F at sea level. The phase change from water to steam carries away the latent heat required to convert 212F water to 212F vapor. If we want to delay the phase change and allow water to reach a temperature higher than 212F at sea level, we have to add pressure, which how a pressure cooker works. A pressure cooker adds an additional 15psi of pressure (basically two atmospheres), which results in water not making the phase change to vapor until it hits 121C/250F.