Traditionally with Kava, always use cool or cold water, milk, coconut water, or any type of liquid would suit your tastes. I’d discard the hot Kava water you have sitting, unless you were careful to heat kava for only short periods of time at measured temperatures, many of the plant’s more heat-stable kavalactones may not survive.
If not sure, discard that batch, and try these directions for proper old world preparation:
Both articles use directions that are good whether you prefer to use a blender, or to just grind the kava with your hands in a bowl of water using a strainer of your choosing.
If you prefer to make a warm tea, we recommend you use the loose kava powder rather than a tea bag; that way, the root will probably be fresher and can swirl around freely in your mug, which makes for more effective steeping. Make sure to heat the kava no more than 140 degrees Fahrenheit; 120 degrees Fahrenheit is considered the ideal temperature for kava tea. Use a kitchen thermometer to measure the temperature of your tea.
Kava root powder is always strained afterward, using any of the preparation methods outlined, which is why we offer many Kava strainers.
In a pinch, though, people have used cheesecloth, tea strainers, loose-weave natural cloth, and even old t-shirts! (Be sure that they are clean!)