11 week Pom throwing up white stuff.

I have a 11 Week Pom he is turning 12 weeks on thursday. i bought him on saturday. Just had a check up today and they gave him the deworming pill along with his second vaccine shot. I noticed that he threw up this white foamyish that looks like saliva twice, He threw up about 30 Min later after the first time. According to Vet Doc this early morning he was doing good but this throwing up stuff just started now. Tempeture here in California where i live is 107 degrees. Could heat cause this or could have he ate something from the floor?? He is always inside the house. Never stepped outside due to not having all the shots