Romans would change in the apodyterium before entering the baths.
This is the changing room, your entry into the baths. An apodyterium had cubicles or shelves where you could tuck away your clothing and other belongings while you bathed. Leaving belongings behind unprotected was a risk, of course, for one of the most common visitors to the Roman baths apparently was thieves.
Privately owned slaves, or one hired at the baths, called a capsarius, would watch your belongings while you enjoyed the pleasures of the baths. One Roman schoolbook quotes a wealthy young Roman schoolboy who entered the baths, leaving his slave behind in the apodyterium. Master reminded slave: "Do not fall asleep, on account of the thieves."
If you were wealthy, you might even bring more than one slave along, as parading your slaves at the baths was a way to show your elevated social status.
Slaves washed their masters and mistresses at the baths.
If you were a wealthy free man or woman, slaves carried your bathing paraphernalia: exercise and bathing garments, sandals, linen towels, and a toilet kit that consisted of anointing oils, perfume, a sponge, and strigils, curved metal instruments used to scrape oil, sweat, and dirt from the body. Slaves might also wash you or give you a massage.
If you were robbed, you could respond by appealing to one of the Roman gods for retribution. A curse on the wrongdoer was written on tablets and offered up to the gods, who were asked to intervene.
Many of these curse tablets were found at the spring at Bath, England. One of them reads: "Solinus to the Goddess Sulis Minerva. I give to your divinity and majesty [my] bathing tunic and cloak. Do not allow sleep or health to him who has done me wrong, whether man or woman, whether slave or free, unless he reveals himself and brings goods to your temple."