I would also retail your client a good aftercare product such as
"Clear it" sold by Zo Zo on here, or even a sterex aloe vera gel (applied twice daily for a few days to help minimise breakouts) as they will more than likely suffer from Perifollicular Oedema which are raised bumps at waxing site waxing. This is due to the trauma caused to the hair follicles by waxing.
Advise the client to avoid any hot baths, showers, saunas or sunbathing which will only make the skin hotter and more uncomfortable.