It is advisable to use hot water for the final rinse out of your tie-dye. Hot water can also help speed up the process and allow the dye to be absorbed into the fabric faster. That said, each fabric has a different maximum temperature that should be considered; for example, natural fibers like cotton, linen, and silk should use water from 60 to 71°C. There are various methods you can try to color your garments, including ice tie-dye or using cold water to prevent the colors from bleeding.