Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Characteristics of the cases (n = 4024)
| Characteristic | Number | % |
|---|---|---|
| Age (mean ± SD) | 5.0 ± 3.6 | |
| Male sex | 2144 | 53.3 |
| Respiratory disease | 305 | 7.6 |
| Asthma | 250 | 6.2 |
| Cerebral palsy | 124 | 3.1 |
| Epilepsy | 110 | 2.7 |
| Warm season | 2192 | 54.5 |
| Warm days (≥26.5 °C) | 1762 | 43.8 |
