Respiratory impairment e.g. respiratory rate >24/min, use of accessory muscles, unable  to complete full sentence, saturation < 92%,   decreased effort tolerance, exhaustion, chest pains.

Dehydration or shock e.g. SBP < 90 mmHg, DBP < 60 mmHg, capillary refill time > 2 secs, reduced skin turgor

Altered conscious level e.g. confusion, agitation, seizures

Others e.g. rapidly progressive or serious atypical illness, severe & persistent vomiting & diarrhea.

Shortness of breath, blue discoloration of lips
Coughing out blood
Persistent chest pain
Persistent vomiting & diarrhea
Fever more than 3 days or recurring after 3 days
Abnormal behavior, confusion, less responsive, convulsion
Dizziness when standing &/or reduced urine production