Possible Hair Dye Scalp Irritation?

My friend helped me dye my hair today. I have natural black hair, & the dye color I was using is dark blonde, because I thought it would turn up as brown (it did). My friend also mixed in a little red dye. She put it all over my hair -- on my scalp & roots & all. I thought she was only going to put it on my hair, but she put it all over. Is that bad? I heard it increases chances of cancer... & It was burning my scalp & eyes too. Is that bad? Like a chemical burn or something? What should I do? It was only burning during the dying process, & it burned less towards the end. It didn't burn after rinsing it off, & it's not burning now. & Also, I'm not sure if this is due to water that was used to rinse off the dye coming down to my face or not, but I have a few red dots on my face... Not so sure if it's from the dye, or just normal acne..