(CNN) -- Nate Wordell, 7, just feels lousy: swollen eyes, cough, high fever, stomach ache and he's dehydrated. Nate has H1N1.
After toughing it out for three days at home, Nate's parents brought him to the emergency room at Children's Hospital Boston, Massachusetts. "The hardest thing for us was that we couldn't stay ahead of the medication or get him to keep any water down," says Nate's father, Michael Wordell of Auburndale, Massachusetts.
Hospitals from coast to coast are bracing for the influx of patients, just like Nate. Children's Hospital Boston has seen a 40 percent increase in patients this week alone.
"This could get pretty bad," says Dr. Anne Stack, clinical chief of emergency medicine at Children's Hospital Boston. "So we are trying to do as much as we can to prepare. But no one knows when it will end."
Many hospitals are creating alternative care sites in parking lots or in office buildings to handle an overflow of patients in the weeks ahead. Children's Hospital Boston has designated a conference room as a go-to H1N1 triage center. "We don't have additional space so we had to think outside the box," Stack says.
The conference room can be "flipped" in 24 hours, Stack says. "All we have to do is wheel in portable sinks, exam tables, computer equipment, cots and curtains. Everything is on standby. We're ready."
But some state health officials say emergency rooms are being unnecessarily strapped by children who don't actually need to be there. Most physicians don't test for the virus or prescribe medicine to healthy children who come in with flu-like symptoms.
"The children we are worried about are those who have influenza symptoms and chronic disease [neuromuscular, heart disease, lung disease] or kids under the age of 2. Their immune systems can't fight things off as well, and the severity of their symptoms can grow rapidly," Stack says.
These high-risk children often report having trouble breathing. That's because H1N1 virus lowers the lungs' ability to pump out enough oxygen.
Intensive care units are also preparing for an increase in patients by tapping into reserve medical equipment, machines like the heart-lung device called ECHMO or Extracorporeal Membrane Oxygenation. ECHMO helps the lungs heal faster by delivering small breaths into the lungs frequently, rather than large breaths less frequently.
"This machine helps a child get 900 breaths a minute, which is one of the best ways we treat critically ill children with H1N1," says Dr. Jeffrey Burns, chief of the Division of Critical Care Medicine and director of the Medical/Surgical ICU at Children's Hospital Boston. Burns has treated over 40 critically ill kids so far this year.
Of the children who have died, two-thirds had underlying health conditions, according to the Centers for Disease Control and Prevention. "The children without a pre-existing condition who died appear to have developed a secondary infection after their system was compromised," Stack says.
However, some parents fear not seeking medical treatment will result in their child's symptoms becoming exacerbated and life-threatening. Experts advise parents be alert for symptoms that develop that are uncommon with influenza. The red flags are rash, trouble breathing, no urinating in six to eight hours, mental disorientation or the inability to keep liquids down.