Universe cold or hot ??
Both, mostly cold.
Majority of the universe is empty space and dark matter, which as far as we know, is cold. Therefore majority of the universe is cold.
However, there are many, many stars in the universe, each of which is very hot, making small areas of great heat. Even though there are so many stars they make up such a small portion of the universe's volume, think of an ant colony compared to a large school, not that big a factor.