Metro Railway, Kolkata — Air conditioner inside metro

This is the third time I am experiencing this. The temperature of the air conditioner inside the metro is so much lowered that I caught bad cold and viral fever. Not once but thrice. It might be lowered during peak office hours when there is a lot of crowd. But what is the necessity of doing it when there's no crowd? It's still the month of March. The temperature isn't so high. Even if it is high, a sudden entry to a very low temperature can cause health disturbance. Kindly note that ill people also travel. So there's no necessity of too low temperature.