(Real Simple) -- From making an omelet to getting some sleep, a little change in the mercury can make a big difference
To make a good omelet, the internal temperature needs to be 160 degrees.
Job at hand: Serving wine
Ideal temperature: White wine, 45 to 50 degrees Fahrenheit; red wine, 60 to 65 degrees.
Why should you care? The image of your mother-in-law making a face as she drinks your warm Merlot will haunt you for years to come.
No thermometer? Try this... "Take whites out of the refrigerator up to 20 minutes before serving; put reds in about 20 minutes before serving," says Kevin Toomajian, a wine expert at Copia, a wine-education center in Napa, California.
Job at hand: Filling a vase for cut flowers
Ideal temperature: Water temperature of 90 to 100 degrees.
Why should you care? "Warm water travels better up the stems, allowing the blooms to hydrate and develop properly," says Cecelia Heffernan, author of Flowers A to Z.
No thermometer? Try this... The water should feel like bathwater. Exceptions: spring-bulb flowers, such as tulips, daffodils, and hyacinths. These prefer a cooler soak (think pool water). Real Simple: How to make flowers last longer
Job at hand: Painting the inside of a house
Ideal temperature: 77 degrees.
Why should you care? At this temperature, most latex paints take only two hours to dry, which means you can move the furniture back into place sooner.
No thermometer? Try this... If you're comfortable standing around in a tank top, you're probably close enough. If it's not quite that warm, don't fret. The paint will just take a bit longer to dry.
Job at hand: Setting curls in your hair
Ideal temperature: Fine hair, 320 degrees; thicker hair, 430 degrees.
Why should you care? A curling iron that is too hot can scorch hair with just five seconds of contact.
No thermometer? Try this... If your curling iron has low, medium, and high settings, choose medium for fine hair and high for thicker hair, says James Morrison, cofounder of the TIGI line of hair products.
Job at hand: Planting bulbs
Ideal temperature: Tender bulbs, soil temperature of 60 degrees and up; hardy bulbs, 50 degrees and cooler.
Why should you care? Because spending the first weeks of spring waiting in vain for a flower is just too sad.
No thermometer? Try this... Plant when night temperatures have been in the right range for two weeks. Plant tender bulbs (gladiolus, elephant ears) in the spring; hardy bulbs (tulips, iris), in the fall.
Job at hand: Being productive at work
Ideal temperature: 72 to 78 degrees.
Why should you care? Studies show productivity drops when temperatures dip below 72 degrees. (More than 78 degrees might make you sleepy, but experts say most offices with A/C don't get that hot.)
No thermometer? Try this... Can't turn up the thermostat? Put a wrap on your chair seat to act as an insulator and raise your body temperature, says Alan Hedge, a professor of ergonomics at Cornell University.
Job at hand: Taking a bath
Ideal temperature: Water temperature of 96 to 104 degrees.
Why should you care? Hot water can break down the skin's protective barrier, which guards against pollution, germs, and bacteria.
No thermometer? Try this... Dip in your hand. If the water is too hot for your hand, it's too hot for the rest of you. Our bodies adjust to high temperatures in about three minutes, but they're still bad for the skin.
Job at hand: Setting your refrigerator and freezer
Ideal temperature: Refrigerator, 32 to 40 degrees; freezer, 0 degrees.
Why should you care? Food will spoil faster if it's too warm, and the quality of the food will change if it's too cold.
No thermometer? Try this... Don't touch those dials! Your refrigerator and freezer should be preset within these temperatures when they arrive from the factory. Real Simple: Best time of day to do just about anything
Job at hand: Filling a fishbowl
Ideal temperature: The water should be room temperature, or 65 to 75 degrees.
Why should you care? Water that is cooler or warmer can leave a goldfish floating sideways.
No thermometer? Try this... Water from a faucet will reach room temperature overnight if it is kept in an open container.
Job at hand: Brewing green tea
Ideal temperature: Water temperature of 170 degrees.
Why should you care? Green tea leaves are more easily burned than black leaves, so they require a lower temperature. Burned tea tastes more bitter and won't deliver a Zen state of mind.
No thermometer? Try this... Use an open pot without a lid instead of a kettle to boil the water. At the first sign of bubbles, pour the water over the tea leaves or bag and steep for one to three minutes.
Job at hand: Making an omelet
Ideal temperature: An internal temperature of 160 degrees.
Why should you care? An omelet should be all it's cracked up to be, says Howard Helmer, an expert with the American Egg Board who holds the omelet-flipping world record (427 in 30 minutes).
No thermometer? Try this... Helmer's method: Whisk two eggs with two tablespoons water. Heat one tablespoon butter in a pan over medium-high heat. When the butter coats the pan, pour in the eggs. Real Simple: How to handle life's little problems
Job at hand: Going to sleep
Ideal temperature: Around 68 degrees.
Why should you care? A good rest requires your body temperature to drop by losing heat into the environment, says Dennis McGinty, chief of neurophysiology for the VA Greater Los Angeles Healthcare System.
No thermometer? Try this... Poke your arms and legs out of the covers, and take off those socks. You'll lose heat without becoming uncomfortable, says McGinty.
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