Get out of the water immediately
Call emergency services if the person has trouble breathing, chest pain, fainting, severe swelling, or widespread symptoms
Rinse the area with seawater
Do not rinse with fresh water
Remove tentacles with tweezers or a gloved hand
Do not rub the skin
Apply vinegar for at least 30 seconds if available and appropriate for the jellyfish species
If vinegar is not recommended for the species in your area, follow local lifeguard or poison control guidance
Soak the area in hot water, about 104 to 113 F, for 20 to 45 minutes
Use a hot shower or hot pack if soaking is not possible
Take an oral pain reliever if needed and if safe for you
Monitor for worsening pain, swelling, rash, vomiting, dizziness, or breathing problems
Seek urgent medical care if symptoms are severe, spreading, or not improving
Avoid alcohol, urine, fresh water, and sand on the sting
Wash the area with soap and water after tentacles are removed
Keep the person still and calm until symptoms improve or help arrives