Heat
Dr. Brian Alters hits the road in the land of the Apache and Navajo. He looks at how plants and animals manage to thrive in a place where it's forty degrees in the shade. They've developed some pretty interesting ways to conserve the water that they need to stay alive.
Just how are buildings made to keep people inside cool? Dr. Brian Fleck and Marc Huot examine housing in hot places. They find that, centuries ago, the Sinagua people knew alot about thermodynamics. And engineers today are using those same ideas to build cooler houses - without relying on air conditioning.
Dr. Jennifer Gardy gets all sweaty to find out how our body deals with extreme heat. It turns out that the brain sends signals to your extremities to radiate the heat out and send the cooler blood back to the core.
Did You Know?
- A large 15 metre saguaro cactus weighs about seven tonnes and took nearly 250 years to grow in the desert heat.
- A desert tortoise stores water in a large bladder about 1/4 of its size. It recycles the same water over and over again, and when the tortoise finally urines, it's a concentrated paste.
- Studies suggest that every dollar spent on passive cooling (shade, verandas etc) could save up to eighteen dollars on active cooling techniques like air conditioning.
- An urban heat island is a metropolitan area which is warmer than its surroundings. The temperature difference usually is larger at night than during the day and larger in winter than in summer. The biggest cause is the asphalt and concrete surfaces which absorb the heat.
- A loss of 10 per cent of body weight due to fluid loss (from extreme heat) can become life threatening.
- Your body temperature is the lowest three hours before waking and reaches its peak around eight o-clock.
Further Reading
Usery Mountain Regional Park Arizonia
http://www.maricopa.gov/parks/usery/default.aspxArizona-Sonora Desert Museum
http://www.desertmuseum.org/Desert Botanical Garden
http://www.dbg.org/Tuzigoot National Monument
http://www.nps.gov/tuzi/Southwest American Indian Ruins
http://www.cupola.com/html/bldgstru/southwst/swest01.htmHow Sweat Works
http://health.howstuffworks.com/sweat.htm
