This may be due to Bacillus cereus, a heat-resistant bacterium commonly found in soil. It can contaminate rice during cultivation, harvesting, or processing. While cooking rice kills most active bacteria, Bacillus cereus spores can survive normal cooking temperatures. If cooked rice is left at room temperature for too long, these spores can germinate, multiply, and produce toxins that reheating cannot destroy, leading to symptoms such as vomiting and diarrhea. Here are tips on how to prevent foodborne illness from reheated rice:

- Store cooked rice properly: Refrigerate within 2 hours of cooking at temperatures below 4°C.
- Reheat thoroughly: Ensure rice reaches an internal temperature of 74°C before consuming.
- Avoid prolonged storage: Consume refrigerated rice within one day to minimize risk.

By following proper food safety practices, you can significantly reduce the risk of foodborne illness and safely enjoy reheated rice.

Read more: https://pmc.ncbi.nlm.nih.gov/articles/PMC7913059/