Water advice

Pushpa
My baby is 4.1 months and is breast fed, the days are getting hotter and just want to know if I should give my baby water. When ppl ask me if I'm giving my baby water and  I answer no,  they tell me that I should b giving her water. Everything a baby needs is all provided in the breast milk I know, so why do ppl think I'm doing wrong in not giving water. 😞