pieboy said: If you do a slo mo on the foaming, I'm not convinced it's the cute blonde actress who gets it. Either a stunt double or another character.
I haven't even seen the full clip but I suspect you're right. Fairly common practice over the years to have the stunt person fall into a cake, or get "sprayed" with some kind of high-powered mess. Sometimes it's for safety.... Sometimes just the actor's ego. (There are always exceptions, from the great Oliver Hardy to Debra Messing doing a poor cake fall recently.)
First time I noticed this was an old WAMTEC cliptape featuring a scene from some terrible movie (Bratty Babies?!). Supposedly, Lisa Rinna (back when she was hot) gets blasted in the face with thick yellow cream (frosting), alongside her husband Harry Hamlin. It's a long clip, and you can instantly tell the two people getting destroyed are NOT Lisa and Harry, but pretty obvious stunt doubles. Excellent coverage, but a letdown for those into "celeb" WAM.
I don't think it's a stunt double, but I think it's a different character all together that gets sprayed. I haven't seen this show but I watched some clips where there is another female firefighter on the show and it looks like her.