* WHAT...Dangerously hot and humid conditions. Afternoon temperatures
102 to 112 expected. Major Heat Risk.

* WHERE...In Arizona, Central La Paz and Parker Valley. In
California, Chuckwalla Valley and Palo Verde Valley.

* WHEN...Until 8 PM MST /8 PM PDT/ Friday.

* IMPACTS...Heat related illnesses increase significantly during
extreme heat events. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.

An Extreme Heat Warning means that a period of very hot temperatures,
even by local standards, will occur. Actions should be taken to
lessen the impact of the extreme heat.

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 9 1 1.

Public cooling shelters are available in some areas. Consult county
officials for more details.

* WHAT...For the Extreme Heat Warning, dangerously hot conditions
with high temperatures in the 90s to near 100 on Thursday with
morning low temperatures in the 70s expected.

* WHERE...Santa Ana Mountains and Foothills.

* WHEN...Until 8 PM PDT Thursday.

* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.

* ADDITIONAL DETAILS...Areas of Major HeatRisk. Very warm overnight
temperatures will limit relief from the heat.

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.

* WHAT...Dangerously hot conditions with high temperatures of upper
100s to low 110s and low temperatures in the 80s expected.

* WHERE...Coachella Valley, San Diego County Deserts, and San
Gorgonio Pass near Banning.

* WHEN...Until 8 PM PDT Friday.

* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.

* ADDITIONAL DETAILS...Areas of Major HeatRisk. Very warm overnight
temperatures will limit relief from the heat.

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

* WHAT...For the Extreme Heat Warning, dangerously hot conditions
with high temperatures in the upper 90s to mid 100s on Thursday
with morning low temperatures in the 70s and lower 80s expected.

* WHERE...San Bernardino and Riverside County Valleys-The Inland
Empire.

* WHEN...Until 8 PM PDT Thursday.

* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.

* ADDITIONAL DETAILS...Major HeatRisk through today. Moderate to
major HeatRisk on Thursday. Warm overnight temperatures will limit
relief from the heat.

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car
interiors will reach lethal temperatures in a matter of minutes.

* WHAT...High temperatures in the 90s below 5500 feet expected.

* WHERE...Riverside County Mountains and San Diego County Mountains
below 5500 feet.

* WHEN...Until 8 PM PDT Thursday.

* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.

* ADDITIONAL DETAILS...Moderate HeatRisk. Warm overnight temperatures
will limit relief from the heat.

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.