I usually add natural yoghurt to cool hot dishes down. Also I made a drink called (variously) lussi or lassi which is natural yoghurt and milk, about half and half with crushed ice and a pinch of ground coriander and salt. This is far better than water for cooling your mouth down. Cheers, Andy
Serve with a dollop of natural yoghurt. Or a side serving of it. That counterbalances the chillies.
The other night we had chilli in tortilla wraps with a bit of grated cheddar and natural yoghurt. They were SPANKIN� GORGEOUS! I highly recommend you try them.
The heat from chillies comes from capsaicin, which, as the link says, is soluble in vegetable oil. If after cooking, there's a layer of oil left on the top, you could skim this off to reduce the heat. Otherwise you could add some oil, reheat, leave to settle, then skim.
like the others said, some yoghurt (probably best on the side as it can curdle if you add it to food while cooking). alternatively, try a little tomato sauce to taste, it works pretty well and can enhance the flavour