hissing and white smoke coming from under the hood out the wheel well?

I pulled into a drive-thru in my '98 1.9 MT and heard this kind of scary sound like a hydraulic hiss or spray, and a quickly dissipating light colored smoke came from the wheels in the front. Car runs fine, temperature gauge reads well, no oil/gas burning. I'll be able to take a look in the bay later, do you guys have any idea what that was?

Btw the entire cooling system on this car was done less than 10k miles ago and if it's relevant, it's hot as hell outside.