The National Weather Service issued the first excessive heat warning of the year for the Phoenix metropolitan area.
The warning, which is in effect from 10 a.m. Wednesday to 8 p.m. Thursday, puts temperature highs at 113 degrees. The warning extends through the evening because temperatures are not expected to cool down much Wednesday night. The Wednesday nighttime low is expected to be in the mid-80s.
For this time of year, 105 degrees is normal, and Phoenix is expecting well above the average, said Chris Breckenridge, a meteorologist with the National Weather Service.
"With the summer solstice, there is going to be a lot of sun," Breckenridge said. "These are two very hot days."
This heat warning could be the first of many; last year, the National Weather Service issued 11 excessive heat warnings for the Phoenix metropolitan area. The first heat warning of 2010 was issued on June 6.
In 2009, the most recent year there is data, there were 110 heat-related deaths in Arizona, according to the Arizona Department of Health Services.
But a really hot summer can mean even more deaths, said Diane Eckles, the office chief in the Office of Environmental Health. The 2005 summer had 225 heat-related deaths.
Most deaths are of males. Between 1992 and 2009, 146 deaths were people ages 25 to 29, Eckles said.
She speculates that this is the group that would be most likely to work outside.
During these extremely warm days, it's important to stay inside if possible, said Ashley Bergeron, RN, a clinical manager in the emergency department of Banner Baywood Medical Center in Mesa.
If you have to go outside, Bergeron suggests staying in the shade and drinking plenty of water to reduce the chance of dehydration and sunburn.
"By the time you feel thirsty, you're already dehydrated," Bergeron said. "So drink and drink continuously. Water is your best bet over sports drinks because they contain sugar and sugar is going to deplete you."
She further suggests that people should avoid alcoholic and caffeinated beverages.
The best way to decease the risk of sunburn is to wear sunscreen and cover up with clothing and hats, Bergeron said.
"You see construction workers outside in the sun and they're wearing long pants and long sleeves with a towel over their head," Bergeron said. "It's important to stay covered."
However, if you're going to be outside by the pool, sunscreen is key. "Use waterproof sunscreen and reapply frequently, since you will sweat it off," Bergeron said.
Once someone reaches dehydration, he or she is at risk for heat exhaustion and eventually heat stroke if medical attention is not sought.
Symptoms of heat exhaustion include being sweaty and clammy, cool to the touch, thirsty and feeling shaky, light-headed and dizzy. By the time it becomes heat stroke, people stop sweating, can start having seizures and eventually become at risk of death.
Medical attention should be sought if a person can't seem to cool off. Parents and caretakers need to be aware that heat-related illnesses can hit children faster than adults, Bergeron said.
So far this year, Bergeron hasn't seen any heat-related illness. Eckles said that there haven't been any reports from Maricopa County to cross her desk yet.
In Arizona, the 2008 average cost to treat heat-related illness was $7,500, Eckles said. That same year, $11 million was spent treating heat-related illness in the state.
"Heat-related illness is mostly preventable by taking precautions," Eckles said.
Parents also need to remember to not leave children in vehicles, even for three minutes, Bergeron said.
While next week's temperatures are expected to be hot as well, it should be a little cooler for the weekend.
"It's cooling down, but (it's) not cool," Breckenridge promised.