The data NOLS has been keeping for over 27 years on field medical incidents tells us that flu-like illness (colds, upper respiratory infections, sore throat, fever, headaches) are among the most common medical complaints. Together with gastrointestinal problems (nausea, vomiting, diarrhea, constipation), flu-like illnesses account for 4 of every 10 reported illness incidents. This theme is seen in other publications on incidents on wilderness trips.
Often these illnesses are a viral infection of the nasal passages and throat that causes a runny nose, sore throat, cough, sneezing, headache, mild fever, muscle aches, and malaise. We believe they are most often transmitted by contaminated hands, and less commonly, although possible, as an aerosol. Wash your hands! Cough into your sleeve, not your hand.
These symptoms are common to many different medical presentations and can occasionally be the initial symptoms of more serious clinical conditions. Gastrointestinal symptoms (nausea, vomiting, and diarrhea) are usually caused by a "stomach bug" or "stomach flu." Respiratory symptoms (cough, congestion, runny nose, sore throat) are usually upper respiratory viral infections. All viral illnesses can also cause a headache, malaise, fatigue, low-grade fever, muscle aches, body aches, etc.--what we refer to as a cold or flu. (Technically the flu is a specific diagnosis and cold is non-specific and colloquial; thus we use the term "flu-like.")
The challenge to the wilderness leader is knowing how to manage these, and deciding when someone is sick enough to warrant an evacuation. You may have months of experience traveling to the ends of the earth and back, but very little experience looking at someone who is obviously sick and lacking any of the dramatic medical problems you studied in your WFR: things like pulmonary embolus, pneumonia, or heart attack.
Whether someone stays in the field or goes home depends in part on how much discomfort they are willing to tolerate. We’re often miserable when we have a flu-like illness, and the misery seems compounded when we’re camping. Also, while many of these illnesses are self-limiting, they can linger for days or weeks, despite all of our remedies. Our wilderness trips often have timetables. Patience and rest are not on the schedule.
In the midst of the influence of these human factors, we can try to base our decision on some guidelines. These are based on expert opinion, and have served NOLS field instructors well.
Evacuation is recommended for flu-like illness if:
- Fever persists >48 hours or is ( >102°F (39°C).
- Stiff neck, severe headache, difficult breathing, or wheezing develops.
- Signs or symptoms of pneumonia develop. This is usually associated with increasing shortness of breath, decreasing exercise tolerance, increasing fever, worsening malaise, and weakness with a predominance of coughing.
- Gastroenteritis with persistent or worsening abdominal pain over 12 hours, spiking fever, bloody diarrhea, or dehydration develops.
- There is an inability to tolerate any oral fluids for more than 48 hours, especially if accompanied by diarrhea volume losses, fever or vomiting.
- A sore throat in conjunction with inability to swallow water/maintain adequate hydration develops.
- An isolated sore throat with fever; red throat with white patches develops.
- There is a headache that does not respond to treatment, is sudden and severe, or is associated with altered mental status.
Treatment Principles for Flu-Like Illness
The management for flu-like illness is based on treating symptoms to help the patient feel better while these illnesses run their course.
- Hydration is important, as always, as is hygiene, especially handwashing. These illnesses are communicable, and we want to avoid spreading this through the group.
- Rest and patience are cornerstones of treatment. Some of these illnesses may respond to antibiotics, but most are self-limiting – they can take a week or more to resolve.
- Pain medications (Acetaminophen or NSAIDs) for headache and muscle aches are fine. Decongestants (e.g., pseudoephedrine), and anti-cough medications can treat upper respiratory symptoms. Bland diets are best for gastrointestinal distress.