D..
Call and ask to talk to the principal. When the school secretary screens your call and says she can't talk to you, tell her that you expect a call before she walks out the door because you are EXTREMELY upset with the substitute teacher. (Leave out the Spanish teacher until you tell her on the phone.) Tell her that you are waiting for that call.
Look, I subbed. So I'm being really honest in my opinion here. She had NO business telling the child no. Specifically because she was the sub, she did not know that this is a kid who doesn't just ask for the nurse for any old reason. She has no excuse for this.
The sub and the Spanish teacher need to be reprimanded.
You know, of course, that he can't go back to school until his temp is normal for 24 hours. I hope he feels better soon. Meanwhile, the school needs the wakeup call.
Dawn