Aushadhi: Nutrition vs Medicine April 2019

Cold foods : cold  temperature / cold or hot virya
Hot foods:  hot temperature / hot or cold virya

In general cold temperature foods will make body cold and need extra energy or Agni to digest. In very hot weather the body has extra heat so eating cold foods does not necessarily make the body cold. In cold weather when the body is trying to keep warm cold temperature foods will dampen the Agni and will have difficulty in digestion and balance 
Cold or hot energy is different, for example, if you eat chili in food, even a salad, to the body it has hot energy and will increase pitta.
By contrast, cold energy foods like coconut or milk, even in a hot drink, will cool the body and increase kapha and may be mucus forming
Cold energy foods taken in cold temperature  will really increase vata and kapha, making the body cold and therefore needs modification ie heat the milk or add saffron or turmeric to mitigate the cold effect.
Hot energy foods like peppers eaten in hot curry will increase pitta more rather than when eaten in a cold salad, therefore you need to balance with other cooling herbs and spices like coriander, fennel, sweet basil etc.
The individual constitution always has to be considered.