Nope, just keep feeding formula on demand, as much as she wants and as often. It's actually not really that hot here, though I know it feels it to us because we aren't used to it, but in normal temps like this (not like 45C), formula or breast milk really is all they need unless your doctor says otherwise (for instance, if you have a baby that isn't eating much and isn't gaining weight and is at risk of dehydration anyway, which is rare). You may find though that she drinks more when it's warmer, so you may want to prepare larger bottles and make sure she's always leaving a little and not completely draining every one.