We are planning to visit Delhi this summer April/May. Heard mosquitos go on rampage. Whats the best way to protect my 4 yr old.

On top of what Diana has written, you might also want to avoid using lotions or creams that are fruit scented when you're there. Mosquitos are attracted to this, I can vouch for this :( Also, if you can, cover your child's sleeping area with a mosquito net. I've also read that eating garlic can be a form of mild protection from those pesky mozzies. The sulphur in the garlic apparently is a deterrent.