Most Indian restaurants I have visited will gladly tell you which foods are hot or mild. They want your repeat business and understand that most visitors have a hard time enjoying Indian food that is hot.
Mmmm....
These are always safe:
Garlic Nan bread, vegetable korma, rice biryani, chicken masala.
I tell them I want 3 on a scale of 1-5, 5 being the hottest.