BABY POWDER!!!!!! Also put some hydrocorosone cream on it. Take lots of showers.

No. . Sadly I just have little boobies- I'm super jealous of yours! My mother inlaw does though (we have a weird super relaxed & open conversation type of relationship). Corn starch (not a giant amount, just rub some under there) is said to help.

Sometimes in the summer I do. A good moisture-wicking bra helps, also switching bras frequently (to different materials and textures help). Baby powder or an after shower powder helps a ton. After you shower, pat dry the reddened (and probably sore area) and pat on some powder under it feels dry and silky to you...that helps a lot to.

YES all the time. UGH.

When it gets uncomfortable I treat it with an OTC hydrocortisone cream, which clears it up in a week or so in conjunction with wearing a new clean bra every day.

To prevent it, I will give the undersides a bit of a swipe with my deodorant to help prevent sweating/bacteria under there. *WARNING* though, I use Crystal Deodorant, which is aluminum free and all natural. (I know the deodorant / breast cancer debate is still very inconclusive, but in this instance I decided to play on the safe side.)

I do sometimes, but since I started using Happy Hooters I haven't had the same issue. As long as I use it each day I don't have to worry about it.

I use Coochy Aftershave Powder to stop this. It is talc free (talc is a carcinogen and found in most baby powders) and really keeps you dry and comfy if you have heavy breasts.

When I get a heat rash under my breasts I use a diaper rash spray. Odd I know but usually using powder under my breasts dry me out bad an I end up with cracking skin

Ugh...all the time. =_='
It sucks so bad when it gets raw too.
I tend to use something like an antiperspirant all over the under side of my breasts and tuck little napkins in there because mine generally are caused from a mix of sweat and the skin rubbing together.

Here's hoping my fellow EF ladies can dodge that bullet this summer though!
^_^