A heat advisory is in effect for Reston and nearby areas from noon to 7 p.m. today.

According to the National Weather Service, heat index values are expected to climb to around 105 degrees and dewpoints are expected to hover in the mid-70s. Heat and humidity could cause heat stress during outdoor exertion or extended exposure.

More from the alert:

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 lightweight 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.

Be aware and be prepared. It is going to be HOT! Drink fluids and stay cool. https://t.co/8JfqAfxgOS

— Fairfax Fire/Rescue (@ffxfirerescue) September 4, 2018