Siem Reap now has an international-standard hospital for emergencies. However, any serious complications will still require relocation to Bangkok.
Angkor Hospital for Children This international-standard paediatric hospital is the place to take your children if they fall sick. They will also assist adults in an emergency for up to 24 hours. Donations accepted.
Royal Angkor International Hospital This international facility affiliated with the Bangkok Hospital is on the expensive side as it's used to dealing with insurance companies.
U-Care Pharmacy Smart pharmacy and shop similar to Boots in Thailand (and the UK). English spoken.