No, it is not recommended to chemically straighten or relax your hair in advance of scalp cooling. This has been suggested in the past as a way of improving cap fit for people with curly or coily hair, but there are much simpler methods of achieving this without permanently changing your hair. The largest problem with chemical processes such as straightening is the damage they do to the hair, and potentially the scalp, which will only be emphasised by chemotherapy. The potential risks of permanently straightening hair before scalp cooling heavily outweigh the benefits.
For more information on getting your hair ready for scalp cooling click herehttp://www.coldcap.com/haircare/getting-your-hair-ready