Fever tracker

Dengue is most dangerous around days 3 to 7 of illness, often just when the fever drops. This tool counts the days and lists the warning signs from WHO guidance.

Key facts

• Phases: fever (days 1 to 2), critical (days 3 to 7, when plasma leakage can start), recovery (from day 8).
• Go to a health facility immediately for: severe belly pain, repeated vomiting, bleeding gums or nose, blood in vomit or black stools, drowsiness or restlessness, cold clammy limbs, difficulty breathing, or no urine for 4 to 6 hours.
• Drink plenty; for fever use paracetamol only, never aspirin or ibuprofen. In Indonesia call 119 for emergencies.
• The tool does not diagnose and stores nothing outside your browser.

Data updated 2026-10-31. Sources: WHO Global Dengue Surveillance; OpenDengue V1.3 (Clarke et al., 2025), doi:10.6084/m9.figshare.24259573; Dinas Kesehatan Kota Semarang; World Bank Open Data; NASA POWER.