Only if your long sleeve shirts come in lightweight fabrics such as cotton. If you wear heavy fabric full sleeve t-shirts or shirts, you‘ll be as good as a fried egg in those scorching summers. Also, remember that the colour you choose is critical. If you are wearing a black coloured full sleeve shirt of dense fabric in summers, then you’ll hardly be able to bear the heat. However, going for a lightweight fabric of black colour keeps you cool, such as a burqa.