Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for difficulty breathing, noisy or labored breathing, rapidly increasing throat swelling, inability to swallow saliva, blue or gray lips, severe confusion, collapse, or unresponsiveness.
And for anyone, someone who:
Seek urgent medical assessment for worsening mouth or tongue swelling, repeated vomiting, inability to drink, persistent drooling, severe pain, or signs of dehydration.
Eye pain, light sensitivity, blurred vision, or redness that continues after thorough rinsing also needs prompt assessment.
Follow the poison center’s or clinician’s instructions about observation and follow-up.
A mild exposure that fully resolves may not require a routine medical visit.
Arrange routine follow-up if mouth soreness, skin irritation, or reduced appetite continues longer than expected, even if symptoms are not worsening.
Children should be watched to make sure they return to normal drinking and urination.
The article also says
To prevent another exposure, place caladium plants out of reach of children.
Wear gloves when cutting or repotting them, wash tools and hands afterward, and avoid touching the face.
Eye protection may be helpful when plant sap could splash.
Teach children not to taste any plant unless a responsible adult has confirmed that it is safe to eat.
Every sign above is quoted from the sofidex article on Caladium plant poisoning. If you are not sure, err upward — it is always reasonable to be checked.