Turning up the Heat!

As the temperature drops, the coats and scarves come out and you probably barely think about heat -unless you leave your coat behind!  Have you ever wondered about how we keep the heat or why we need it? Or how animals and humans differ? What would you need to survive in the extreme cold?

All creatures have an optimal temperature their body needs to achieve proper function.  Warm-blooded creatures (endotherms) can regulate their body so it stays at a constant temperature.  So naturally if you were in an extremely cold environment your body will have to work overtime to stay warm! How is the heat escaping?

On the Move

Heat radiates out and diffuses from an area of high concentration (your body) to areas of lower concentration (everywhere else) through either conduction or convection.  Conduction is transfer of heat between two solid surfaces.  So, if you sit in the snow heat will escape via your direct contact with the snow.  Convection is the transfer of heat between a mass (i.e. you) and a moving fluid or gas. So, if you are standing outside and an icy wind blows past you, it is pulling heat away from you.  Same thing is true if you jumped in the Arctic Ocean.  Your heat will escape in the passing chilly water.

The heat from a warm-blooded human or polar bear in the Arctic is constantly trying to escape and move away from the body through these two mechanisms.  The goal in these extreme environments is to either contain your body heat and stop its movement, or at least slow it down so the internal body mechanisms can keep up with production.

Capture the Heat

What are some ways your body stays warm and what are some things you can do?

  • Fuel your fire – make sure you are well fed and hydrated so your body can burn extra calories to maintain your core temperature.
  • Shivering – This is actually a warning that you are too cold. Your muscles spontaneously contract to burn calories and generate heat to increase or maintain your core temperature.  If you are shivering, you should get somewhere warm or put on more layers.  It is one of the last lines of defense your body has to prevent hypothermia.
  • Layer up – Adding clothing layers traps air and slows the transfer of heat. This insulation, especially if your coat is waterproof, is a powerful way to keep the heat in.
  • Shelters – such as igloos in the artic, or your own house are designed to trap heat and keep you and your environment warm.

Animals versus Humans – how do they capture the heat? What do you think makes animals and humans different when it comes to the cold? Animals have evolved many different adaptations to allow them to cope with extreme cold.

Polar bears have both an extra layer of fat and special fur. Their special coat features two types of fur: long oily guard hairs and short insulating hairs. Together these different types of hair help the polar bear stay warm. The oily guard hairs are hollow allowing them to trap warmth and bring it close to the skin.  They also provide an oily outer layer which prevents the polar bear from getting wet and losing heat via convection. The shorter insulating hairs help polar bears stay warm by trapping heat close to the skin. Under their fur, polar bears have black skin which is good for absorbing the rays of the arctic sun. Plus, their coat is white, which is helpful for camouflage, and reflects light making it a poor conductor of heat.

Whales, seals, walruses are all examples of marine mammals that use blubber to stay warm.  Blubber is just an extra layer of insulating fat, which keeps their internal heat from escaping. Having blubber means those animals can swim in the cold arctic ocean without getting a cold or hypothermia.

Otters are an interesting marine mammal that can survive in the icy ocean, but don’t have blubber.  Otters have a super dense, double-layered coat of up to a million hairs per square inch!  That fur is designed to be water-proof and capture pockets of air.  All that air makes them float and works just as well as a layer of blubber.

Humans on the other hand must add something to their body to stay warm.  The simplest solution for early humans was to wear the skins and pelts of these animals. We basically borrowed the animal adaptations by making clothes out of animal skin – everything from seal and caribou to rabbit and bear. Eskimos even make waterproof parkas from the skins of marine mammals.

Modern fabric technology:

Scientists and engineers have been able to replicate these animal adaptations in a variety of ways.

  • Fleece is similar to wool and very efficient at keeping you warm by trapping air and adding insulation to your layers. Guess what – it’s made of plastic polymer! Its polyester fiber can even be made from recycled bottles.
  • Nanowire tech – a newer technology that features special metallic fibers that trap air and can even be used to generate heat when a charge is run through them.
  • Adaptable smart fabric –Astronauts wear a temperature regulating suit under their space suit that circulates liquids and helps them maintain a constant temperature. Scientists have been studying a way to create something similar to this for everyday use.  Imagine wearing a light weight shirt that adjusts to the temperature no matter where you are. Almost like having a central air system right next to your skin.
  • Synthetic furs and fabrics- Also we can spare the rabbits and other animals and manufacture faux fur and other coverings that keep the adaptation and hold the slaughter.

Bundle up your layers and stay warm this winter just like a polar bear!

Fall into Hibernation With Fun Science!

Beautiful leaves, fruitful harvests, and cooler weather are all things we think of when we picture fall.  It is a transitional time from the sweltering summer months to the frigid winter months.  For many creatures, fall is also a transitional time when they prep for hibernation.

What exactly is hibernation?

Bears snoozing in a den is what many of us probably imagine when we think hibernation, but a lot of different types of animals hibernate and experience similar processes.  Hibernation is a state of inactivity and metabolic slowdown in endotherms i.e. warm-blooded organisms. It is characterized by low body temperature, slow breathing and heart rate, and low metabolic rate.

Many ectotherms (i.e. cold-blooded organisms) seem to hibernate via a similar process called brumation.  Remember that the main thing that differentiates warm-blooded and cold-blooded creatures is that warm-blooded organisms can self-regulate their temperature and metabolic responses.  Whereas cold-blooded organisms’ metabolism reacts in response to their environment.  So cold environment = slower metabolisms for all ectotherms versus cold-environment = hibernation for some endotherms but not all.  Fish seem to hibernate but are an example of an ectotherm slowing down in response to the cold.

Hibernation is a considered a period of energy-saving torpor.  Torpor is a state of decreased physiological activity in an animal and includes a lower body temperature and metabolic rate.  Some animals experience what is called daily torpor, which refers to a period of low body temperature and metabolism lasting less than 24 hours.  For instance, hummingbirds experience a state of torpor just at night and have been known to hang upside down from their perch while in this state.

Hibernation in general occurs in winter and the opposite of hibernation is called aestivation, which occurs in the summer months.  Many invertebrates and amphibians have an aestivation cycle that helps them survive hot, arid seasons.

Why hibernate?

Whether it is hibernation or aestivation it is all about surviving extremes.  It is a way for animals to survive difficult conditions.  For instance, winter for a bear or squirrel means cold temperatures, not a lot of food, very little camouflage cover.  Despite being in a vulnerable torpor state, being out in those conditions seem way riskier. The risk of vulnerability must have been outweighed by the benefits of hibernation for bears and other creatures to evolve this unique mechanism.

Prep for hibernation

Bears, for instance, have a period prior to hibernation where they eat and drink in excess to build up their fat stores for hibernation.  Gorging themselves on nuts, berries and other food sources while they are around help them survive once they go into torpor and hibernate for several months.  They also have a transition period where they aren’t hibernating but their metabolism is beginning to slow so they start to eat less and sleep more.   The creation of a cozy den or nest is also essential for hibernation. This keeps body heat contained, protects from the elements, and conceals the hibernating animals.

Can humans hibernate?

You might feel sleepier in the winter months, but humans never evolved to hibernate.  Part of that reasoning is that since we evolved in equatorial, tropical Africa where there is a consistent food supply we would not have needed to hibernate to escape harsh conditions.  We also would have been a top predator, so less likely to need hibernation to avoid predators.  We are also bigger and most hibernators are small with the obvious exceptions here and there (bears).

Our hearts are also different from other mammals that hibernate.  Our hearts contract in response to calcium. So, if our heart gets too cold, there is a buildup of calcium and we go into cardiac arrest.  Mammals that hibernate have a special pump that gets rid of excess calcium, which means their hearts continue to beat at much lower temperatures.

Scientists are interested in engineering ways for humans to hibernate because it would aid in long-term space travel.  Astronauts must exercise 6 hours a day in space to prevent muscle and bone atrophy, which might be avoided if they could hibernate.  Hibernation obviously would reduce the amount of supplies they would need, and could protect from radiation.  A year in space right now is the max an astronaut can do without significantly increasing the odds that they’ll get cancer and other side effects due to radiation.

National Sandwich Day- Discover the Science of a Sandwich!


Science of the Sandwich: turn your favorite, triple-decker into a tower of nutritional power!

Here’s how not to build a sandwich: Start with wimpy white bread, smear on the mayo really thick, and then pile on an entire package plus a dozen individually wrapped slices cheese. Instead of a hero, you’ve got yourself a nutritional supervillain. The good news is, it’s simple to recast that sandwich. Here’s how to do it right, whether you want to ensure a nutritional lunch, additional muscle growth or just plain old good health.


Image Source: Pixabay.com

All great sandwiches start with great bread. The more nubs and nuggets you see–which indicate fiber content–the better. When shopping, select varieties whose ingredient lists start off with “whole-grain wheat” or “whole-wheat flour.” But know that “wheat flour” isn’t the same thing as “whole-wheat flour”–it’s the “whole” part that contributes the fiber. And don’t go just by color; some wheat breads made with refined white flour (wheat flour that’s been stripped of the coarse, fiber-rich kernel) are colored to look tike whole-wheat bread. Kaiser rolls, baguettes, focaccia, and most pitas (except whole-wheat pitas) are considered “white” bread. Even sourdough, rye and pumpernickel are often actually colored and flavored white-flour breads. A good benchmark is a nutritional score of at least two grams of fiber per slice. Whole-wheat breads may have a smidgen of fat, but not enough to worry about.

Smart bread choices include Freihofer’s Stone Ground 100% Whole Wheat, Wonder 100% Whole Wheat, Nature’s Cupboard Natural l0-Grain, Arnold Country Wheat, and Rubschlager Danish Style Pumpernickel.


Image Source: Pixabay.com

Most manufacturers of reduced-fat cheese have finally figured out how to make a product that maintains its classic flavor after the calories and fat have been minimized. More good news: Trimming the fat from these cheeses doesn’t keep them from remaining valuable sources of calcium that keep your bones strong and healthy.

Deli counter: Take a number at the deli counter, it’s worth waiting in line for the likes of Yarlsberg Light Swiss and Alpine Lace Swiss.

Prepackaged aisle: In the prepackaged-cheese aisle, check out Sargento Light Deli Style Sliced Provolone and Sargento Light Deli Style Sliced Swiss. Kraft makes a very serviceable fat-free American cheese product called (surprise!) Fat Free Singles. Kraft also makes Fat Free Swiss Singles, but the flavor seems indistinguishable from that of their American slices (the possibility exists, of course made of stone).


Image Source: Pixabay.com

With all the lean choices now available, why to heavily processed, high-fat deli meats oozing with nitrites? Roasted and smoked turkey breast, baked ham and lean roast beef are all better picks.

Just make sure to buy actual meat and not meat blends (baked ham versus ham luncheon meat, for example). The first place to go is the deli counter, where a guy in a white smock will actually weigh and cut the fresh chunks of meat for you into any thickness your heart desires.

For great deli-counter meats, try Healthy Choice Honey Maple Ham, Healthy Choice Honey Roasted and Smoked Turkey Breast, Healthy Choice Italian Style Roast Beef, Boarshead Ovengold Turkey, and Boarshead Baked Ham.

If you insist on shopping in the prepackaged-meat aisle, be careful: If it looks like it’s been preserved in hair gel, perhaps it’s a bit too processed. When you buy pure meat (such as turkey breast, ham carved from the bone, and roast beef), you can actually pull the slices apart with the “grain.”

Some tasty and healthy prepackaged-meat options are Healthy Choice Deli Traditions Garlic & Herb Roast Beef, Healthy Choice Deli Traditions Cooked Ham, Healthy Choice Oven Roasted Turkey Breast Variety Pack, Butterball Fat Free Honey Roasted & Smoked Turkey Breast, and Butterball Fat Free Smoked Turkey Breast.


Image Source: Pixabay.com

Sandwiches give you the perfect opportunity to sneak in a few of those five servings you’re supposed to eat each day. Start with dark-green lettuce (such as romaine or red leaf), and choose vine-ripened tomatoes for the most flavor. Great additions to any sandwich include roasted red peppers (from water-packed jars), bottled sweet and hot peppers, water-packed artichoke hearts, red-onion slices, fresh basil, fresh watercress leaves, fresh baby spinach leaves, shredded carrots, and even cucumber slices for extra water, fiber and bulk, a triad that increases satisfaction without increasing calories. In fact, one whole cup of vegetables has only 50 calories, but can be loaded with vitamins and minerals. Options include:

* 1 cup carrots–19,000 IU of vitamin A

* 1 tomato–138 mg potassium; lycopene

* 1 cup red peppers–282 mg vitamin C

* 1 cup spinach–245 mg calcium


If you’re a true mayonnaise lover, there’s no need to go without. Fat-free and reduced-fat varieties of mayonnaise and Miracle Whip can just as creamy and fat-laden as their oily counterparts. Besides the classic French’s yellow mustard, try country-style honey mustard or any of the gourmet varieties now available in most markets.  Fortunately, plenty of healthy and tasty toppings are out there, although some of them can carry hefty amounts of sugar.

Fat-Free Sauces (two tablespoons)

* Salsa-

* Tomato-basil sauce-

* Fat-free Italian salad dressing-

* Black bean sauce-

* Light soy sauce-

* Teriyaki sauce-

* Hickory-smoked barbecue sauce-


To add zip to your fat-free mayo, mix in some cayenne pepper.


Mayonnaise and Miracle Whip: At 11 grams of fat per tablespoon, mayonnaise should come with a prescription for Lipitor. Try fat-free varieties–or mustards, tomato sauces, steak sauces, soy or most Asian sauces.

Full-Fat Cheese: There’s no reason to buy full fat-cheese anymore, not when the reduced-fat selections taste just as good. However, because of their higher water content, fat-free varieties typically don’t melt as well, so keep an eye on the stove to prevent burning.

White Bread: Need we remind you that white bread is lacking in many nutrients? Ease the switch to whole grains by opting for whole-wheat bread before graduating to grainy, multigrain slices.


Mayonnaise-Free Cole Slaw: Combine one cup of prepackaged cole slaw mix (shredded cabbage and carrots) and a quarter-cup of ranch dressing.

Tropical Fruit Salad: Combine two cups of mixed fresh fruit (you can use any combination of cubed melon, papaya, mango, pineapple, berries and oranges).

Brown Rice/Black Bean Salad: Toss together one cup of cooked instant brown rice, one-third cup of canned black beans, two chopped green onions and two tablespoons of  Italian salad dressing.

Discover more about National Sandwich Day on ABC News.com or read about the top 31 sandwiches in America