(This article was updated at 1:45 p.m. after a severe thunderstorm watch was issued for the area.)

The National Weather Service has again issued a heat advisory for an area including Fairfax County, as the sizzling hot temperatures that we’ve felt all week just won’t go away.

From the NWS alert:

…HEAT ADVISORY IN EFFECT UNTIL 7 PM EDT THIS EVENING…

The National Weather Service in Baltimore MD/Washington has
issued a Heat Advisory, which is in effect until 7 PM EDT this
evening.

* HEAT INDEX VALUES…Around 105 this afternoon.

* IMPACTS…Risk of heat-related illness for those without air-
conditioning or those outdoors for an extended period.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A Heat Advisory means that a period of high temperatures is
expected. The combination of high temperatures and high humidity
will create a situation in which heat illnesses are possible.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks
in shaded or air conditioned environments. Anyone overcome by
heat should be moved to a cool and shaded location. Heat stroke
is an emergency — call 911.

In addition, the NWS has issued a severe thunderstorm watch for the area that will be in effect until 9 p.m.

A severe thunderstorm watch has been issued for parts of DE, DC, MD, NJ, PA, VA, WV until 9 PM EDT pic.twitter.com/i8usDXbyxk

— NWS DC/Baltimore (@NWS_BaltWash) July 14, 2017

Reston is under a severe thunderstorm watch, along with most of the Washington, D.C. area, this evening.

The National Weather Service says the area is under the watch until 7 p.m.

Storms should begin in the area about 3 p.m. and may bring damaging wind and hail, says the NWS.

Reston Now will update this story if the watch changes to a warning.