Why men are asked to remove shirts in hindu temples?

We can see in many of the hindu temples especially in kerala and kanyakumari men should not wear shirts inside the temple. This is because of a scientific reason to make aperson healthy. Let us see that now....A temple can be compared to the human body.The two main parts of a temple are

Garbhagrahamm - a stead containing the image of God,

The Vimanamn - a stucture over the Garbhagraham.

The Garbhagraham:

                          When Westerners saw Indian temples for the first time, they thought they were very unhygienic. By the very nature of their conception the temples could not have many doors and windows. There could only be one door, and that too was very small. It is no wonder then that those Westerners went away with the impression that the temples were dingy, dark and dirty, and that even fresh air could not enter them. By comparison, their own churches were airy and clean and had many big doors and windows through which light and fresh air could easily enter and keep them hygienic.Today not one person in India will be able to say why temples were not provided with windows and many doors. 

So when asked we also felt inclined to agree that our temples are unhygienic; no one could argue that in these temples lived the most healthy people and that no disease had been allowed to enter. The people who used to pray and worship there happened to be some of the healthiest people, in the true sense of the term.
Why?

Why Garbhagraham is dark?

                        The Vimanam over the Garbhagrahamm attracts cosmic rays and the rays are directly given to the garbhagraham which is very dark. Since the  cosmic rays cannot stay in dark areas immediately it is emitted out of the garbhagraham. The devotees who are outside the garbhagraham with their bare chest will get these  cosmic rays.

This makes the people who used to pray and worship there happened to be some of the healthiest people.

Why garbhagraham has only one door?

                        The  darkness of the sanctum reflects its function as a "womb house,". Sanskrit word garbha means womb. As i said earlier a temple can be compared to the human body the womb house is similar to the womb of a mother. Since the womb of a mother is dark and it has only one door to enter it clearly represents the human body.