Winter: Adana is rather cold in the winter, so bring suitable clothes. If you are visiting a Turkish family, is good to wear layers because many homes have a family room heated with a wood burning stove and it gets HOT - you will heat up very quickly and want to take some layers off. Then, if you go to another part of the house, like the bathroom, it will be cold outside of the stove-heated room.
Toiletries and Medical Supplies: There are plenty of pharmacies around (eczane) and you can get quite a bit of medicine over the counter without a prescription, such as antibiotics, if you know the general name of your medicine. If you don't the pharmacist will look in a book for your brand name and try to find the Turkish equivallent. If you feel sick and can describe your ailment (or can pantomime it if the pharmacist doesn't know english and you don't have a Turkish dictionary) the pharmacist can often help you if you don't think you need a doctor. Tampons may be difficult to find, so you may want to bring some with you just in case, so you don't have to hunt them down. However, they are for sale at larger stores, like Gima Supermarket, and perhaps at pharmacies. The word for them is the same in Turkish. You can buy all other toiletries in Adana, shampoo, etc.
Camping/Beach/Outdoor Gear: Summer: Bring lightweight breathable clothing, as it is hot and somewhat humid during the day. Bring a light jacket or shawl if you are going out in the evening as it can get a bit cool sometimes. If you are a woman, you probably want to wear a skirt around knee-length or trousers, jeans (older Turkish women don't wear these) or cropped pants when you go out in public - if you wear shorts, you may get some looks because people in Adana generally cover up more than Turks in the Med resort towns. Even in the hottest days of summer many men will be wearing trousers. You can wear shorts if you are a man though, that's ok.
Miscellaneous: Women can wear sleeveless tops but I haven't seen many Turkish women dressing this way in public. I do though. I'm not saying that people are super-conservative here, some are very fashionable and some girls wear skimpy tight things while other women are more modest and keep their heads covered, you see all sorts. If you are going to a more rural area of the city, don't wear really tight clothes. Also, if you are visiting a local family for dinner, you may all eat seated on the floor (depends on the family), on a thin blanket, so wear something that you can comfortably sit in. Wear comfortable shoes because Adana is a rather busy city and you'll be dodging people at times.