Just as a heat wave is expected to hit Moses Lake, people are being advised to avoid all contact with waters in the area.
The Grant County Health District says the lake is unsafe for citizens because of the toxic blue-green algae outbreak.
Though not always toxic, algae blooms are not uncommon in Grant County water.
The algae, a type called Cyanobacteria, looks like greet paint floating on the water. However, the algae can also be blue-green, red or brown.
Contact can be fatal for pets and can cause anything from a rash to severe nausea and vomiting in humans.
Testing of water near Connelly Park showed toxin levels four times higher than Washington state recreational guidelines.
If reports are received by the health department of people becoming sick or pets dying, it will then post danger signs and close the lake completely.