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.
The figure shows the complete protection afforded by a watch strap, incomplete protection on the arm from a combination of clothing and sunscreen, sunburn where a patch of skin was exposed by movement of clothing and not covered with sunscreen, tanning on the unprotected skin of the hand.
