Help! What rashes is this?

It has been a week plus. At 1st i thought it just normal heatrash n will go away with just bathe + lotion (happened b4 n it worked). But this rashes doesn't seem to. Baby sleep in aircon, even on rainy days. I bought eczema lotion n try too but doesn't seem better. And it is only on her front body and some on arm, nowhere else. Anyone knows what it could be?