11month baby girl I have....lot of prickly heat in neck under arms what can o do

A. hi u   heat rash typically occurs due to blocked swead pores. wear cotton , lightweight ,loose clothes. run water on affected areas, areas prone to sweating.air dry it. let the skin breathe. avoid powders as it may block the pores further. if it doesn't disappear in 4 to 5 days, or increases, or with fever consult paediatrician