Last one was about general known wisdom of old old traditions, ancient knowledge in India about how to keep cool in summer - without AC of course. A lot of it had to do with food, and there are some specific recipes and traditions. Here are a few.
In north there are wonderful melons in season in summer, and these help keep cool. Especially watermelon. Eat them without any added sugar or cream or any of the usual stuff. They are good all by themselves, as an afternoon activity to help keep cool. Pack pieces for a lunch along with a sandwich.
In south there are some wonderful and easy recipes to keep cool which one needs most of the year in some parts - one is a yogurt rice that is not just a mix of the two separate ingredients as in the rest of the country, but more of a recipe. Of course a casual mix as a lunch or even breakfast is good on hot days - keeps one cool. but the special recipe is something else.
You will need some mustard seeds, some dry long red chillies, some curry leaves (not bay leaves used in dressy north Indian food but small dark green leaves used in south and west) and salt, apart from organic yogurt (for culture) and oil for seasoning, preferably coconut oil or sunflower oil. You should be able to get most of this at the Indian grocery store and some possibly over the internet, like ethnicgrocery.com (I heard of this site long ago, there must be a lot of them by now) and so on. Of course it might be better to order only dry stuff over the internet unless you are sure of your dealers delivering the oil without spilling.
Try setting your own yogurt to begin with, for a good reason, by warming milk at night to a comfortable temperature - somewhat like a baby-bath for a summer day - and stir a teaspoonful of the organic yogurt in it by mixing it with the warmed milk and letting it in, and stirring gently. cover and leave over pilot light or over radiator or near it, so it is at roughly human body temperature through night. Look in the morning if it is set. If it does not work ask an Indian colleague's wife or mother or someone at the Indian grocery for tips and help.
When you are fairly confident of your being able to set yogurt you are ready for the next stage.
You will need rice cooked and cooled and milk ready to set (warmed to body temperature or a little more, not much more) for the next stage; milk should be enough to mix with the ready cooked rice and a bit more so the whole mix feels neither liquid nor dry but a comfortable mix. when mixing do not break or mash rice into the milk, be gentle. Then - this is the important part - set yogurt in this mix by stirring in a spoonful of yogurt mixed with a little milk, gently, just the way you have been doing to set yogurt from milk. Cover and leave on pilot light or on radiator or near radiator, in the place where you have been successful at setting yogurt for yourself.
You can do all of the above or do a shortcut by just mixing ready yogurt with ready cool rice, before the next step; the first tastes better, the second is easier.
Next and final step on the morning after when the yogurt is already set into the rice is seasoning. This is what is a basic southern seasoning.
Heat a little (- a tablespoon for one person or two for a family of four or proportionately more at logarithmically increasing quantity, that is, the more the ready yogurt rice the less the increase in oil, so three tablespoons of oil for a dozen people is enough -) oil in a small pan over low fire, with red chillies (one for one person, two for four, four for a dozen) and test it by throwing in a mustard seed till one pops, and then throw in ( half a teaspoon for one person, one teaspoon for four people, two for a dozen) and cover and wait for them all to pop, the throw in curry leaves and cover and switch off the fire and let the curry leaves cook while the oil cools a little. A couple of minutes and mix this with the ready yogurt rice mix which you can add a little salt as per your taste - less is better since it can always be added for those who like it more but a little is necessary for a proper taste.
And there you are with the most wonderful basic lunch or breakfast for summer, to which you can add a little quantity of dry fried vegetables (again, with very little oil) to complete the meal for lunch, or a half teaspoon of an Indian mango pickle for taste if this is too bland for you.
Of course the chillies in the mix are not necessary to eat - they have added a minimum flavour to the oil, and for more flavour squeeze them in the plate with your spoon or fork when eating so their juice is added to the yogurt rice (this is midway) unless you are hardcore chilli aficionado and you can take it - then eat one along with the rice. It will bring some tears and some sweat along with taste, and you will cool more.
Have fun.
If you have any doubts about your capacity for red chillies refrain from overdoing it, and it is ok to start without them and see if you like it - though they do enhance the taste and experience, but avoid for small children or even unaccustomed preteens anyway.
Tip:- if anyone old or young feels the sharpness of chillies have milk or buttermilk ready to drink instead of water to overcome the effect of chillies, it works far better. This is general tip for any food with chillies or hot pepper.