Hot Dogs and Cool Cats
Objectives
- Be able to talk about temperature.
- Understand normal temperatures for people and pets.
- Understand how insulation works for animals and people.
- Measure actual temperatures.
- Understand how extreme hot temperatures, especially in closed cars, and extreme cold temperatures can affect pets.
Rationale
The impact of hot and cold temperatures on pets can be a matter of life or death for them. Investigating these impacts can help students understand temperature and its effects.
Curriculum Connection: Alberta Education Program of Studies
Science
Grade 2: Hot and Cold Temperature
- Recognize the effects of heating and cooling, and identify methods for heating and cooling.
- Describe temperature in relative terms, using expressions, such as hotter than, colder than.
- Measure temperature in degrees Celsius (°C).
- Recognize that the human [or animal] body temperature is relatively constant and that a change in body temperature often signals a change in health.
- Identify materials that insulate animals from the cold; e.g., wool, fur and feathers; and identify materials that are used by humans for the same purpose.
- Describe ways in which temperature changes affect us in our daily lives.
Activities
Cold
Have students brainstorm what they do to keep warm on a really cold day. What can animals do to keep warm? Talk about insulation:
- winter clothes
- fur coats - do some pets have thicker fur coats?
- amount of body fat - are some pets skinnier than others?
What about those bare paws on our pets or uncovered ears? Have students think of ways to help pets in cold weather:
- shorter walks and keeping cats indoors
- not leaving pets in cold cars
- providing coats and booties
- more food
- insulated doghouses with doors
For more work on insulation, look at the American SPCA lesson on How Fur Works. See the ASPCA Cold Weather Tips for protecting pets from extreme temperatures.
Hot
Have students brainstorm what they feel like on a hot day. When is it too hot? What can they do to cool off?
Do they think animals get too hot? What can make them too hot? ( too much exercise on a hot day, being shut in a car on a warm day) Why is harder for animals? Can they just take their coats off? Are they always able to move to a cooler place? What if they are shut in a car or tied up? How do dogs cool off? (panting, getting in cool water)
How hot is too hot?
Veterinarian Cate Rinaldo, a volunteer with United Animal Nations, points out that dogs don't have sweat glands all over their bodies like humans do, so the main way they can cool off is by panting, which isn't very efficient.
Once a dog's body temperature gets over about 41C — normal temperature is around 38C — “the result is everything from nerve damage, heart problems, liver damage, systemic organ failure, and it happens fast, within a matter of minutes," she says.
http://www.msnbc.msn.com/id/30723511/
Use this information to help students compare:
- normal body temperatures for people and dogs
- temperatures in the classroom, outside on a hot day
Help students understand the difference between warm, hot, very hot.
How can we prevent pets from overheating?
Have students brainstorm ideas and them compare those to the ASPCA Hot Weather Tips.
Measuring temperature
Even on relatively mild-temperature days, the internal temperature of a vehicle left in the sun quickly gets very warm - the average rise in one hour is 22°C says lead author Catherine McLaren at Stanford University in Palo Alto, California.
On 16 cloud-free days in Northern California, the team measured a car's inside temperature at 5 minute intervals for one hour post-parking. Ambient temperatures on the study days ranged from 22°C to 35°C.
They found that, regardless of outside air temperature, the car heated up at a similar rate - gaining 80% of its final temperature within 30 minutes. Cars that started out comfortable 22°C, for example, rocketed to over 47°C after 60 minutes in the sun. And keeping the windows open a crack hardly slowed the rise at all.
See full article and additional Car Temperature Chart for more information.
- Start by asking students if they have noticed whether it is much hotter inside a car than outside on a nice day.
- Have them estimate how much hotter.
- On a sunny day go out to the parking lot and have students measure temperatures outside and inside the car. Try airing out the car and seeing if it cools off. Then see how fast it warms up again.
- Ask students what they have observed:
- Is it hotter in the car than outside? How much hotter?
- How long does it take to get really hot?
- Does it make a difference if the windows are open?
- Do you think the car is too hot for a pet?
- What should we do to make sure pets don’t get too hot? (never leave in cars unless it is very cold)
- Have students make up a poster warning of the dangers of pets left in hot (or cold) cars.
Resources
- Louisiana State Medical Society: “Heat Exposure in an Enclosed Automobile”
- “How hot do cars get?” Original Fahrenheit chart on car temperatures
- Additional newspaper articles:
- Hot dog poster
- Winnipeg Humane Society hot and cold weather pet tips