An official website of the United States government
Here’s how you know
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.
... an immune reaction, resulting in hives and skin rashes. Researchers are ... of cool temperatures. Direct contact with a cold object, such as an ice ...