ORANGE COUNTY, Va. (WRIC) — Planning to head to Orange County or Spotsylvania County for a dip in Lake Anna? The Virginia Department of Health is warning people to think twice about swimming in certain areas.

A harmful algae bloom has been found in the Upper Pamunkey Branch of Lake Anna. The algae can cause skin rash and gastrointestinal illnesses. So unless you want to spend your holiday weekend itchy and puking, it may be best to take your swim somewhere else.

The department of health says the samples were taken on June 23 and unsafe levels of the algae, called cyanobacteria, was found.

VDH has identified the area shaded in red as where the harmful algae bloom is found. (View full map:

People should avoid any activities that could result in them accidentally ingesting the lake water.

VDH explains that the bloom can be found in the part of the lake stretching from “the upper inundated waters of the Pamunkey arm of the lake downstream to just above the confluence with Terry’s Run.”

If you suspect you may have accidentally swallowed the dangerous water, contact the Virginia Harmful Algal Bloom Hotline at 1-888-238-6154.