Im sure it will just be heat rash hun. Ella has it really badly for the past week and I was worried it was something else as it was getting worse and worse and spreading all down her back, but the HV has seen it and said just to keep her cool take her clothes off her and wet her with a flannel, but dont dry her, just leave it to evaporate to cool her down.
Hope the docs confirn thats its only heat rash in this weather Im sure it is. Let us know