certain household items increase the temperature inside the house in summers

Here are some of the factors:
1. Global Warming due to thinning of ozone layer that protects from the heat released by the sun
2. Less trees, more factories. If you would notice the air is alot warmer in urban than in rural areas
3. Overpopulation. More people = more carbon dioxide emission = more hotter
4. Air/Gas Pollution

For example, your fridge creates heat. A fridge works this way: A coolant is first compressed outside the box. This creates heat by the adiabatic effect of the increased pressure. It is then released through a nozzle inside the box, thus creating cold. But as much heat is created outside the box as cold inside. Hence opening the door of a fridge in order to cool down the kitchen is not a good idea. It only uses a lot of electricity to make both heat and cold.

But it is in very small extend and in no way could this influence the temperature outside. In my humble opinion, if you feel the heat outside was less a problem when you were young it is simply ... because you were young.

I am now 65 years old and living in Norway. I remember not so long ago I still enjoyed going skiing in the coldest part of the winter. Today, even the sight of snow on a postcard makes me freeze! ;-)

It is only the process of getting older, my friend. Unpleasant? Perhaps. But the French singer Benabar sings this (translate from French) "Young girls who are lucky become old ladies." Or, as a Norwegian singer puts it: "We want to live a long time but we don't want to get old." ;-)

Everything absorbs some heat. It is a matter of how much does it hold. Everything using electricity or gas emits heat. How much are you willing to accept as a price of using the technology. If you spend your energy worrying about heat distribution, you will have little energy left for actually coping with the heat in your marvelous country. YOU have to chill out to accommodate for it. I live in one of the hotter cities in my country. I have a toleration zone for what heat I can stand and still function effectively. I weigh options but i do not turn off my life. I buy light colors except where I like dark! I have tile floors rather than wood or carpet because it holds cool and deflects heat. I do have leather furniture because I like it and because it is animal skin and discharges heat rather than storing it. We have cotton blankets that keep the chill of the air conditioning away but do not hold heat.

I work on my computer. I have a model that gives off somewhat less heat than some others but i will not stop using it. I do try to do most of my computing before the sun rises and after it sets though.

I try not to waste energy because of the cost and because it creates a higher dependence on foreign oil anf gas --- not good for the economy.

 Houses designed before air conditioning came into widespread use were better ventilated, but, beyond that, a refrigerator will raise the inside temperature a little due to its heat exchange process. Most of the other things you cite shouldn't have that much effect.

Densely populated areas with a lot of air conditioning probably do see a slight rise in temperature, but it really shouldn't vary more than a few degrees at most.

A lot of what you have noticed is how our bodies react to the heat and humidity. To some extent we manage these better as children, but many of us end up getting so used to air conditioning we can't live without it.

Technology, of course, does have a price. If India has lost green space due to development it has lost much of what nature can do to make life easier.