There are a lot of old time remedies to prevent the prickly heat, one of them is to apply corn starch to the areas where it is most likely to strike. I recommend the Gold bond products mentioned above as they have other medicinal ingredients to help heal and soothe those prickly heats away.
The best remedy for prickly heat, as proven by my wife who has suffered for years, is natural yogurt. Unfortunately, this is only a short term cure, not a preventative. But when you get to the point where you feel like you want to scratch your skin off, natural yogurt really does the trick.
Well there are some prickly heat powders and creams that can be used to protect from severe itchiness and inconsistency but you have to protect yourself from heat so that you can save yourself from prickly heat.
I believe your looking for goldbond medicated powders for that fast cooling relief. Lol. Hope this helps. www.goldbond.com/frequently-asked-questions.html