Answers
Get expert answers from our doctors on wilderness medicine, outdoor safety, and health topics for your outdoor adventures.
What should I do in an Extreme Heat Watch?
Getting an Extreme Heat Watch is your signal to get ready. A Watch means conditions are favorable for an extreme heat event that is not yet certain[1], so you get a short head start before it arrives. Use it. The National Weather Service advises planning to suspend major outdoor activities...
What are normal symptoms of wildfire smoke exposure, and what are the warning signs?
Most of what wildfire smoke does to you is uncomfortable, not dangerous. It irritates the eyes and airways, causing coughing, a scratchy throat, irritated sinuses, headaches, stinging eyes, and a runny nose.[1] For a healthy person, these usually ease once you get to cleaner air. Some symptoms are a signal...
Who is most at risk from wildfire smoke?
Wildfire smoke reaches everyone, but it doesn't hit everyone the same. The people most at risk are those whose heart and lungs are already under strain. In someone with asthma or COPD (a serious long-term lung disease), smoke can set off severe breathing trouble that ends in the emergency room,...
Is it safe to work outside in wildfire smoke?
Working outside in wildfire smoke carries real risk, and unlike a workout, you often can't just call it off. Breathing the fine particles in smoke can reduce lung function, worsen asthma and other heart and lung conditions, and bring on coughing, wheezing, and difficulty breathing. The harder and longer you...
Is it safe to exercise outside in wildfire smoke?
In light smoke, a workout outside is fine. The smokier the air and the harder you go, though, the more you should hold back. The harder and longer you exert yourself, the more smoke particles you pull deep into your lungs.[1] Let the AQI set the limit. For a healthy...
Do cloth or surgical masks protect against wildfire smoke?
Not well. When the problem is wildfire smoke, cloth and surgical masks are the wrong tool. Cloth face coverings should not be relied on for smoke, and one-strap or surgical masks are not built to seal to your face, so they offer only some protection when a proper mask is...
Is wildfire smoke dangerous to your health?
Wildfire smoke is more than a bad smell. It can genuinely harm your health. Its fine particles, known as PM2.5, are the main pollutant of concern.[1] Each is roughly a thirtieth the width of a human hair, small enough to reach deep into your lungs, and some can even get...
At what AQI should you wear a mask outdoors?
No official AQI tells you to put on a mask outdoors. No health agency sets a mask-on number. What a mask can do depends on what's dirtying the air, and it helps most in one situation: when fine-particle pollution is high, which usually means wildfire smoke. In those situations, a...
At what AQI should you move a workout indoors?
Deciding when to take a workout inside comes down to two things: how high the AQI (air quality index) is, and how hard you mean to go. No agency sets an exact number for moving exercise indoors. The harder and longer you work out in dirty air, the more of...
What AQI is safe for kids to play outside?
Children don't handle dirty air the way adults do. Kids' lungs are still developing, and they breathe more air relative to their body size than adults do.[1] That makes children more sensitive to air pollution than adults[2], so the line for bringing them in sits lower. On a clean-air day,...
What AQI is safe for exercising outdoors?
No single AQI number turns outdoor exercise from safe to unsafe. The reality is that this is a complicated decision, and a single number oversimplifies. What matters is how much pollution you actually take in. That depends on how dirty the air is, how hard you're breathing, and how long...
Is it safe to exercise outdoors with asthma when air quality is poor?
Having asthma doesn't mean giving up outdoor exercise when the air is poor. Most people with asthma can stay active in poor air by easing off, timing it for cleaner hours, and following their asthma action plan with quick-relief medicine on hand.[1][2][3] You'll just need more care than someone without...
What are the warning signs of heat stroke?
Heat stroke is the emergency end of heat illness. It is the most serious heat-related illness, and without emergency treatment it can cause permanent disability or death.[1] The warning sign that matters most is a change in how someone is thinking. Confusion, slurred speech, or passing out in a person...
What is the first aid for heat exhaustion?
Heat exhaustion responds well to quick, simple care. Get the person out of the heat to a cool spot, and take off extra clothing, including shoes and socks.[1] Cool them with cold compresses, or have them wash their head, face, and neck with cold water, and give cool water to...
When should you call 911 for heat illness?
Heat stroke is a medical emergency, so call 911 for emergency medical care immediately.[1] What tips you off is how the person is acting, not just how hot they are. Call 911 for anyone who is overheated and confused, slurring their words, or not fully conscious, since those point to...
What are the symptoms of heat exhaustion?
Heat exhaustion is your body struggling to keep up with heat. It sets in when you lose too much water and salt, usually through heavy sweating. The signs tend to build gradually. You might get a headache, feel nauseated, dizzy, weak, or very thirsty, and you'll usually be sweating heavily....
What do the AQI numbers and color categories mean?
One number on the air quality index stands in for several pollutants at once. The AQI tracks five major ones: ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Whatever pollutant is worst that day sets the number you see. That single number is sorted into six color-coded...
How do you keep the air inside your home clean during a smoke event?
Start by sealing up your house. Shut the windows and doors, and set any air conditioner to recirculate so it isn't pulling smoky air inside[1]. Sealing helps, but it doesn't make the air clean. With everything closed, indoor smoke still sits at roughly 55 to 60% of the level outside,...
How do you tell heat exhaustion from heat stroke?
As the air around you gets hotter, your body stops shedding heat into it and starts taking heat on, leaving evaporating sweat as the only cooling left. That evaporation costs water and salt, and heat exhaustion is what happens when sweating spends more of both than the body can spare....
How can I prepare for a heat wave?
The heat wave you're least ready for is the first one of the summer. Your body does adapt to heat, but slowly, so ease in rather than tough it out. About 75 to 80 percent of heat acclimatization is complete only after seven days of moderate exertion in the heat,...
What is an Extreme Heat Watch?
An Extreme Heat Watch does not mean the dangerous heat has arrived. The National Weather Service issues a Watch when conditions are favorable for an extreme heat event but its occurrence and timing are still uncertain. Forecasters can see the ingredients coming together, yet they can't say for certain that...
Do N95 masks protect you from wildfire smoke?
Of everything in wildfire smoke, the fine particles called PM2.5 matter most to your health. They're tiny; a human hair is about thirty times thicker than the biggest of them. Some travel deep into your lungs, and a few may even reach your bloodstream. Most healthy people recover quickly from...
What regulations cover heat illness for workers in the United States?
Currently there is no federal OSHA standard specifically regulating workplace heat illness, though OSHA published a proposed rule in August 2024 that would become the first federal heat standard. Until a federal standard is finalized, OSHA enforces heat safety through the General Duty Clause of the Occupational Safety and Health...
How do I prepare for a trip to Joshua Tree National Park this Fall?
Fall offers ideal conditions for visiting Joshua Tree National Park, with comfortable daytime temperatures around 70°F and clear skies perfect for hiking and stargazing. November brings pleasant weather, but desert conditions remain harsh and require serious preparation. The park has no water sources, gas stations, restaurants, or supply stores inside...
How do I prepare for a trip to the Great Smokey Mountains National Park this Fall?
Fall offers some of the best conditions for exploring the Smokies, with comfortable temperatures ranging from the 70s-80s in September down to the 50s-60s by November at lower elevations. However, elevation makes a significant difference. Temperatures at higher elevations like Newfound Gap (around 5,000 feet) typically run 10-20°F cooler than...
When is the air quality safe for outdoor activities after wildfire smoke?
The Air Quality Index (AQI) tells you when it's safe to be active outdoors during wildfire smoke events. The EPA uses a color-coded scale from 0 to 500, with six categories ranging from green (good) to maroon (hazardous). For outdoor activities, AQI values of 50 or below (green) represent good...
Is bear spray effective, and how do I use it correctly?
Bear spray is highly effective at stopping aggressive bear behavior. Research shows success rates of 90-92% in deterring bears, with 98% of people carrying bear spray uninjured in close-range encounters. The spray stopped undesirable bear behavior in 92% of brown bear incidents, 90% of black bear incidents, and 100% of...
How can I tell if it's too dangerous to be outdoors during a thunderstorm?
If you can hear thunder, you're close enough to be struck by lightning—making it immediately too dangerous to be outdoors. Lightning can strike more than 10 miles away from the location of rainfall, meaning blue sky overhead doesn't guarantee safety. The safest approach is to monitor weather forecasts before outdoor...
How do you tell the difference between black bears and grizzly (brown) bears?
Don't rely on color alone: both bear species range from black to blonde. Grizzly bears have a distinctive shoulder hump between their front shoulders, creating their highest point when viewed from the side. Black bears lack this hump and instead have their highest point at the middle back or rump....
How do you tell the difference between a coral snake and other snakes?
The traditional rhyme helps distinguish coral snakes from similar-looking harmless snakes, but experts now recognize this method has serious limitations. True coral snakes have red bands directly touching yellow/white bands, with both red and black bands being roughly the same width, separated by narrower yellow/white bands that completely encircle the...
What should I do if I see a bear while hiking?
If you see a bear while hiking, stay calm, do not run, slowly back away while talking in a calm voice, and make yourself appear larger by slowly raising your arms above your head. Most bears want to avoid humans and will leave the area if they detect your presence....
How do I prevent mosquito bites?
Use EPA-approved repellents with DEET or picaridin on exposed skin, wear long sleeves and pants, and treat clothes with permethrin for best protection against mosquitoes. Use proven bug repellents on your skin. Apply EPA-approved repellents containing DEET (20-30%) or picaridin (20%). These work for 6-12 hours and are safe...
How can I stay safe around rattlesnakes?
Most rattlesnake bites happen when people interact with snakes on purpose, not by accident. The Wilderness Medical Society reports that most bites occur when people try to catch, kill, or bother snakes. This often happens when people have been drinking alcohol. The best protection is learning about snake behavior and...
What should I do if I get altitude sickness?
Altitude sickness occurs when you ascend too quickly for your body to adjust to lower oxygen levels. The most important first step is to halt all further ascent and rest at your current elevation [1]. Never continue climbing higher with any symptoms of altitude sickness, no matter how mild they...