The answer to 'how to unclog emergency plumbing' is to first try a plunger or a drain snake. If that doesn't work, you may need to use a chemical drain cleaner or remove the trap under the sink. However, for severe clogs or if you're not comfortable doing it yourself, it's best to call a professional plumber.
When dealing with a clogged drain, it's important to act quickly to prevent further damage or flooding. Start by using a plunger to try and dislodge the clog. If that doesn't work, move on to a drain snake or auger, which can help break up the blockage. Be sure to follow the manufacturer's instructions carefully when using these tools. If the clog persists, you may need to use a chemical drain cleaner, but be cautious as these can be harsh on pipes. As a last resort, you may need to disassemble the trap under the sink to access the clog directly.