A heat alert was issued for Fredericton on Saturday.

The advisory from the City of Fredericton says humidex levels are predicted to be between 35 and 39 for much of the day in New Brunswick's capital, with the expected peak in late afternoon.

Humidex values take into account temperature and humidity and are typically higher than the recorded temperature.

The alert, in effect for Saturday only, says those with the highest risk of heat-related illness should be monitored — the elderly, the overweight, children under four and people with certain chronic health conditions.

Fredericton is one of four cities selected by Health Canada to participate in a heat alert pilot project, which was used for the first time July 7.

Saturday's advisory is a Level 1 Heat Alert, the lowest of three possible levels. Symptoms of excessive heat include heavy sweating, paleness, muscle cramps, fatigue, dizziness, headache and nausea. If you suspect someone is suffering from heat stroke, call 911 immediately.