Summary

• In week 25 of 2017 (June 19–25), emergency department visits for all causes were slightly higher among children under two years of age (+8%) and stable in other age groups. Hospitalizations were stable across all age groups.

• Among seasonal spring and summer illnesses, amid a heat wave, there was a predictable increase in emergency department visits for heat-related illnesses (HRI) (+94%). The largest increases were among adults aged 75 and older (1,169 visits, or +105%). Diagnoses of hyperthermia were more frequent among children and adults under 75, while diagnoses of dehydration and hyponatremia were more common among children under two and adults aged 75 and older.There was an increase in visits for isolated fever among children under 15 and adults aged 75 and older (+20% and +10%, respectively), as well as for malaise among 2- to 14-year-olds (+21%) and adults (+19%). Hospitalizations are on the rise for asthma (+16%) among adults aged 75 and older and for allergies (+20%) among children aged 2 to 14 and adults, with a doubling of hospitalizations observed among those aged 75 and older.In addition, visits for insect bites are on the rise in all age groups except among those aged 75 and older, and for burns among children under two and adults aged 75 and older (+12).