Month: November 2022

Here’s a new fact about spring, summer, fall, and sometimes even winter, now that climate change has blurred seasonal boundaries: sizzling heat may be on the way, or currently blanketing your community.

High temperatures stress the body, leading to thousands of heat-related illnesses and deaths every year in the US. Creating a personal heat plan can help you stay safe when the heat index soars.

Caleb Dresser, MD, MPH, is the health care solutions lead for C-CHANGE, the Center for Climate Health and the Global Environment at the Harvard T.H. Chan School of Public Health, and an emergency medicine doctor at Harvard-affiliated Beth Israel Deaconess Medical Center. Below we interview him about who, how, and why heat harms. Then we’ll help you create your personal heat safety plan.

Interview edited for clarity

Who is especially vulnerable during hot weather?

High temperatures can affect anyone. But some people — children, outdoor workers, people who are pregnant or have health problems or disabilities, and older people — are more likely to experience harm when temperatures rise. For example:

• Young children, especially babies, have less physical capacity to deal with very high temperatures.
• People working outdoors may not have access to shade and could be performing physically intensive labor. They need adequate hydration, adequate breaks, and access to a cool space during break time, as OSHA guidelines spell out.
• People with chronic medical conditions, such as kidney disease or heart disease, may have difficulty adapting physiologically to hot weather, or may be more susceptible to its health impacts.
• And some people living with disabilities or certain neurological conditions may have difficulty with thermoregulation — that is, controlling the temperature of their bodies — or may not be able to take actions that keep them safe, such as taking off layers or moving to a cool area.

Which weather patterns create dangerous levels of heat?

Dangerous heat is the result of both high temperatures and high humidity, which interfere with our ability to cool off by sweating. In dry areas, extremely hot temperatures can be dangerous on their own.

Danger zones vary across the United States and around the world. But hospital use and deaths rise once we get above threshold temperatures. The threshold varies in different places depending on whether bodies, cultures, and architecture are adapted to heat.

For example, here in New England, where some people (particularly those of limited means) may not have access to air conditioning, we see increases in healthcare use and deaths at a lower temperature than in the American South, where people and organizations may be more used to dealing with hot weather.

When does hot weather become dangerous to our health?

Risk goes up the longer hot weather sticks around.

One hot day can put some people at risk. A stretch of several hot days in a row during a heat wave is particularly dangerous because it can overwhelm people’s ability to adapt. Eventually people run out of physiological reserves, leading to greater health harms and greater need for medical care.

Surprisingly, spring and early summer are particularly dangerous times because people and organizations aren’t as prepared for hot weather.

How to create your personal heat safety plan

Five key points to help you create a personal heat plan are below. Americares offers further information through heat tip sheets developed with the Harvard C-CHANGE team that are tailored to people in different health circumstances.

Planning is important because intense heat is occurring more often: a Climate Central analysis found 21 additional risky heat days, on average, for 232 out of 249 locations between 1970 and 2022.

• Stay ahead of hot weather. Check apps, websites, TV, or radio for updates on weather today and in coming days. If local weather alerts are available by phone or text, sign up.
• Have a cooling plan. When temperatures soar, you need to spend as much time as possible in cool spaces. Plan options if your home is likely to be too hot and unsafe to stay in. You may be able to stay with a neighbor or family member who has air conditioning until a heat wave passes. Many cities and towns have neighborhood splash pads for children, and open cooling centers or air-conditioned libraries, public buildings, or community centers to everyone — sometimes even overnight. Spending time in air-conditioned businesses or malls, or in a shady green space like a park, may help too.
• Sip plenty of fluids. Water is the best choice. Skip sugary drinks and avoid caffeine or alcohol.
• Use fans correctly. Fans help if surrounding air is relatively cool. If air temperatures are very high, it’s important to dampen your clothes or skin to help keep your body from overheating, and move to a cooler location, if possible.
• Know your personal risks and the signs of heat-related illness. If you have health problems or disabilities, or take certain medicines such as diuretics, talk to your doctor about the best ways for you to cope with heat. It’s also essential to know the signs of heat-related illnesses, which range from heat rash and sunburn to heat cramps, heat exhaustion, and heat stroke. This chart from the Centers for Disease Control and Prevention describes the signs to look for and what you can do, particularly when heat becomes an emergency.

About the Author

Francesca Coltrera, Editor, Harvard Health Blog

Francesca Coltrera is editor of the Harvard Health Blog, and a senior content writer and editor for Harvard Health Publishing. She is an award-winning medical writer and co-author of Living Through Breast Cancer and The Breast … See Full Bio View all posts by Francesca Coltrera

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

Picture this: you’re with friends in an unfamiliar forest using only a map and a compass to guide you to an upcoming checkpoint. There are no cell phones or GPS gadgets to help, just good old brainpower fueled by a sense of adventure as you wind through leafy trees and dappled sunlight.

This is not an excursion to a campsite or a treasure hunt. It’s a navigation sport called orienteering — a fun way to get outside, exercise, and maybe even help fight cognitive decline, according to a 2023 study.

What is orienteering?

Orienteering combines map and compass reading with exercise. Competitors (“orienteers”) race against a clock to reach checkpoints in outdoor settings that can range from city parks to remote areas with mountains, lakes, rivers, or snowy fields.

“You can go out in a group or on your own. You get a very detailed map and navigate your way to checkpoints that record your time electronically,” says Clinton Morse, national communications manager with Orienteering USA, the national governing body for the sport in the United States.

Because orienteers are racing the clock, they might run on trails, hike up hills, or scramble around boulders. That’s for foot-orienteering events. There are also orienteering events with courses geared for mountain biking, cross-country skiing, or canoeing.

How might orienteering affect thinking skills?

A small 2023 study published online in PLoS One found a potential link between orienteering and sharp thinking skills.

Researchers asked 158 healthy people, ages 18 to 87, about their health, activities, navigation abilities, and memory. About half of the participants had varying levels of orienteering experience. The other participants were physically active but weren’t orienteers.

Compared with study participants who didn’t engage in orienteering, those who were orienteers reported

• having better navigational processing skills (recognizing where objects were, and where participants were in relation to the objects)
• having better navigational memory skills (recalling routes and landmarks).

The study was observational — that is, not a true experiment — and thus didn’t prove that orienteering boosted people’s thinking skills. But the link might be plausible.

“Aerobic exercise releases chemicals in the brain that foster the growth of new brain cells. And when you use a map and connect it to landmarks, you stimulate growth between brain cells,” says Dr. Andrew Budson, lecturer in neurology at Harvard Medical School and chief of cognitive and behavioral neurology at VA Boston Healthcare System.

Where can you find orienteering opportunities?

There are about 70 orienteering clubs across the United States, and many more around the world (the sport is extremely popular in Europe). To find an orienteering event in your area, use the club finder tool offered by Orienteering USA.

How can you get started with orienteering?

People of all ages and athletic levels can take part, because orienteering courses vary from local parks to wilderness experiences. Costs are about $7 to $10 per person for local events, or $25 to $40 per person for national events, plus any travel and lodging expenses.

To make orienteering easy at first, Morse suggests going with a group and taking things slowly on a short novice course. “You don’t have to race,” he says. “Some people do this recreationally to enjoy the challenge of completing a course at their own pace.”

The trickiest part is learning to read the map. Morse’s advice:

• Turn the map as you change directions. Hold the map so that the direction you’re heading in is at the top of the page. For example, if the compass indicates that you’re heading south, turn the map upside down, so the south part is on top and easier to follow.
• Create a mental image of what the map is telling you. If there’s a fence along a field on the map, build a picture of it in your mind so you can recognize it when you see it, even if you haven’t been there before.

Tips for safe and enjoyable orienteering events:

• Dress appropriately. Wear comfortable clothes including long pants, good walking shoes, and a hat.
• Lather up. You’ll be outside for at least an hour, and you’ll need sunblock and possibly tick and bug spray depending on the terrain. Preventing tick bites that can lead to Lyme disease and other tick-borne illnesses is important in many locations.
• Bring some essentials. Pack water, a snack, sunblock, bug spray, and your phone. (Keep the phone turned off unless you need to call for help.)
• Use good judgment. Know that the shortest route on the map won’t always be the best, since it might take you up a hill or through thick vegetation. It might be better to go around those areas.

Once you learn the basics of orienteering, you can make it more physically challenging (and a better workout) by going faster and trying to beat your previous times, or by signing up for a more advanced course that’s longer and requires more exertion and speed.

And no matter which event you take part in, enjoy the adventure. “You’re not just following a path, you’re solving puzzles while being immersed in nature,” Morse says. “It’s a great way to experience the outdoors.”

About the Author

Heidi Godman, Executive Editor, Harvard Health Letter

Heidi Godman is the executive editor of the Harvard Health Letter. Before coming to the Health Letter, she was an award-winning television news anchor and medical reporter for 25 years. Heidi was named a journalism fellow … See Full Bio View all posts by Heidi Godman

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

We’re bombarded with advertisements that tout all sorts of health benefits for vitamins and supplements, including improved memory. A May 2023 study of older adults suggests that a daily multivitamin can do just that — improve your memory enough such that it can function as if you were three years younger.

So, should you take that daily multivitamin? Let’s take a close look at the study.

Who took part in this multivitamin study?

This research is part of a larger study examining the effects of a multivitamin and/or cocoa (the main ingredient in chocolate) on cardiovascular and cancer outcomes. A prior sub-study found that a daily multivitamin improved thinking and memory — at least when evaluated with cognitive testing completed by phone.

For this study, 3,562 participants were willing and able to perform some tests of thinking and memory on a home computer. Half received a multivitamin; the other half received a placebo.

The participants identified as 93% white, 2.5% African American, and 1.4% Hispanic, so the results may not be generalizable. They were also well educated: more than half had completed college. In both groups, the average age was 71.

How did the researchers test memory?

The investigators evaluated the participants’ thinking and memory at baseline and after one, two, and three years.

For the memory test, participants were asked to memorize 20 words shown consecutively on a computer screen. Immediately after viewing these words, they had to type in as many words as they could remember (this was the primary measure of memory). Fifteen minutes later, they also typed in all the words they recalled (a secondary measure of memory).

Other secondary measures included:

• a novel object discrimination test (is this object the same or different from one recently shown?)
• an executive control test (in an array of nine arrows, is the central arrow red or blue?).

The participants repeated all of the tests one, two, and three years later.

What were the results of this study?

The two groups differed in immediate recall at year one:

• Those who took a placebo went from immediately recalling an average of 7.21 words at baseline to 7.65 words (a difference of 0.43 words)
• Those who took a daily multivitamin group went from 7.10 words at baseline to 7.81 words (a difference of 0.70 words).

This result was statistically significant. Additionally, these small effects held up at years two and three. By year three, the placebo group immediately recalled an average of 8.17 words and the multivitamin group immediately recalled 8.28 words.

No differences occurred between the two groups on secondary memory and executive function tests.

How can a multivitamin improve memory?

The authors note that low levels of vitamins B12 and D have been linked to cognitive decline and dementia. In a subset of participants who had their blood drawn, the levels of these vitamins did rise in the multivitamin group.

It seems plausible that a few of the 3,562 participants had low levels of these or other vitamins that are important for thinking and memory. In the placebo group, the few who had vitamin deficiencies would likely show less improvement in memory after their baseline tests, or a small decline. By contrast, those few participants in the multivitamin group with deficiencies would have them corrected by the supplements and, therefore, would perform relatively better.

Although this is just speculation, it would explain the small but seemingly real results — results that replicate the researchers' prior study, which used a telephone cognitive test to show thinking and memory benefit from a daily multivitamin.

It’s also worth noting that practice on memory tasks — the so-called practice effect — could contribute to small improvements shown from baseline to year one and year three.

Should you take a multivitamin to improve your memory?

The authors admitted that the effect of the multivitamin on immediate memory was small and may not be noticeable. However, they pointed out that this small effect could be important at the level of an entire population.

My opinion? You shouldn’t bother taking a multivitamin to try to improve your immediate recall of 20 words from 8.17 to 8.28 words. But it is worth speaking with your doctor about whether you could have a vitamin deficiency in B1, B6, B12, D, or any other important vitamins. I see several patients in my clinic every week who have startlingly low levels of vitamin D and B12. Your doctor may want to measure these levels. Or they may suggest simply taking a multivitamin daily.

If, after reading this article, you’ve decided to take a multivitamin, please check with your doctor or pharmacist about which one would be best for you. Make sure that they review any other vitamins, supplements, and medications you take to avoid rare but serious interactions.

About the Author

Andrew E. Budson, MD, Contributor; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Andrew E. Budson is chief of cognitive & behavioral neurology at the Veterans Affairs Boston Healthcare System, lecturer in neurology at Harvard Medical School, and chair of the Science of Learning Innovation Group at the … See Full Bio View all posts by Andrew E. Budson, MD