Help my hair seems really dry and brittle after having highlights put through it?

Yesterday afternoon I had my hair highlighted at our local village hairdresser. Unfortunately as I was under the hairdryer waiting for the bleach to work, the fire alarm sounded and the shop had to be evacuated including me wearing the rubber cap and so on. Anyway we were outside for about half a hour so I think my my has been damaged due to the bleach being on too long. Is there anything I can do.