Most Lattes are served hot.
However if you want to order a cold Latte you can order an Iced Latte and most places that serve hot Lattes will also serve or make a cold ice latte for you if you request it.
I prefer a hot latte on a cold winters day but during winter time I will order an iced latte.
Although the coffee shop here doesn't specifically sell iced lattes they will make them when you want them.
So if you want a cold latte ask for a ice latte and they will usually make you one.
However most lattes are served hot and you could allow it to cool down and drink the hot latte cold.
Lattes are steamed hot and are usually between 135 and 150 degrees F, but they only have a thin layer of microfoam.