I have, over the years, advised many mothers to leave their babies loose - i.e. unwrapped; the mothers, and indeed their extended families, have often secretly disobeyed my advice, for who wouldn't like their baby to be snugly wrapped in pink and lacy wraps?
What the parents are missing is, of course, the logic behind my advice. Unable to understand, even when I have explained that keeping the baby open allows her the freedom to move her body, hands and feet in whichever direction she wants, they continue to wrap the baby, and to do that tightly, which means that not only does the baby not get to move her limbs here and there, she does not even get to move them one tiny bit ... even when she has an urgent desire to do so!
Now, the fact remains that sensory input is THE ONLY WAY to encourage neural development in an infant. Babies who are constantly stimulated do much better at older ages than those who are not. This is reflected in their acquiring motor milestones earlier, their ability to be more dextrous and flexible and their speed of development of finer motor milestones as well.
In addition, in tropical climates, and particularly in the summer and autumn months, and to some extent in the months of monsoon (with extremely high humidity), the child who is tightly wrapped can get rashes such as heat rashes, chapping of the skin inside the arm-pits, groins, buttocks, and so on, and can also get itchy rashes that cause a lot of discomfort and excessive crying.
Thus my recommendation: Do not tie the baby tightly; rather, if it is cold outside, cover her up with a blanket, but by and large, let her sleep well by her own self.