You can eat pasta salad cold.
Pasta Salad can be served and eaten cold or at room temperature.
Some people prefer to eat the Pasta Salad while chilled and some like to warm the Pasta Salad up before eating it or serving it.
I prefer my Pasta Salad to be warmed up slightly as I don't really like chilled foods unless it's really hot out.
In the winter months I prefer warm Pasta Salad and other warm foods and in the summer months when it's hot out I prefer the Pasta Salad cool.
It just depends on your personal preference as to whether you want the Pasta Salad heated or served chilled as it can be eaten either way.