Hi everyone hope everyone had a good Holidays.I have a question concerning my Fig Trees  which are in my detached Garage trees are in pots sitting on wooden pallets my concern is Thursday night is supposed to go down to 5 degrees,what can I do to keep the trees from freezing should I wrap the pots with pink insulation and cover trees with a tarp.Please guys and gals give me some input what to do.Your advise will be greatly appreciated. Thanks

Unless someone knows what your temp zone is and what is the normal cold temperatures for January and February, it will be difficult to provide precise advice. 
 I suggest before you find a better solution from others, why not bring the pots inside to a cold (or cooler) place before they freeze to death.

Jeff,  Better safe than sorry.  If you have insulation available, use it.  Plastic doesn't do much to stop heat loss, so using a tarp with blankets or quilts would be better.  Usually the first night of a cold snap isn't too bad - it takes a while for the cold to completely chill a structure - the temperature tends not to get as low inside as it would in an extended cold snap.   
But, as Ottawan said, it's difficult to give precise advice not knowing your exact circumstances - there are a lot of variables.  How cold the garage gets in comparison to the outside temperature - if the temperature goes down to 5, what will the indoor garage temperature likely be?  Is the garage tight and less likely to get very cold if it's windy?  The amount of mass in the garage (the greater the mass, the slower the temperature drop).  The age of the fig trees (older trees are less likely to be damaged).  If the trees were hardened off, healthy, and well into dormancy. 
If you haven't already, stick a thermometer in the garage and one outside.  After a while you'll get a feel for what to expect in the garage for various temps and wind conditions.  (So you'll know when to really panic, LOL.)
Best of Luck.

If you mean 5 deg inside the garage, maybe you need to add a heater for the night. You don't say how many trees you have, and how much of a project it will be to insulate, and cover, etc. Might be easier to insulate the garage, and adding a heater, since this is going to be an annual event, if you keep growing figs.

Figs are reasonably tough- probably safe down to low to mid 20's as potted plants in your garage. Outdoors I find my varieties good even after 7 or 8 degrees for established plants of Desert King, Magnolia (Brunswick), Eastern Brown Turkey, Celeste, and White Marseilles. I do NOT protect my fig trees, and normally have NO dieback. An important factor in my success with figs is my long growing season. My figs don't have freezing weather until November or December due to the nearby Delaware Bay. Inland areas of Cape May County, New Jersey often freeze up to a month before my area.

Right on, Palmfan.  Figs are tough and hardier than most folks fear.  The 5 degree cold snap Jeff was worried about took us down to 0 degrees here the first night (with a whistling wind), and 5 degrees the second night.
My garage is attached with cement floor, and wood with shingles - no insulation.  The temperature the first night went down to 30 degrees in the garage.  The second night of the cold snap it went down to 23 degrees.  It was five degrees warmer outside than the previous night, but it was colder in the garage the second night because it had already cooled considerably, and the daytime high temp was only 9 degrees!
For mature, hardened, healthy, dormant figs these garage temperatures are NOT a problem.  We have had -10 degree temperatures here for nearly a week that drove the temperature inside the garage close to 10 degrees F.  It was NOT a problem for the uncovered figs, as Palmfan's 7 or 8 degrees illustrates. 
Think about the tarp towers you see covering figs in the North East.  Carpeting or blankets, some insulation, and a tarp.  Imagine that was the only protection you had on a 0 degree night - not nearly enough to keep you "warm" or figs either.  But figs overwinter just fine with this little bit of protection.
Mother Nature has devised a survival strategy - dormancy.  Keeping figs cold protects them.  Heating them in the winter (with all the best intentions) makes them more susceptible to cold injury.   Steady cold temperatures that fluctuate slowly will protect your figs better than any heating setup. 
There are exceptions and qualifications.  Young trees, or heavily fertilized trees are more susceptible to cold damage.  Make sure your plants are hardened off.  Check your garage or shed temperatures so you get an idea of what to expect during extreme weather.  If it dips below 10 degrees inside, or drops quickly, think of adding insulation and/or mass to keep it warmer and slow the fluctuation. 
Believe me I know how precious these plants are.  I know how radical this sounds to some of you.  But all I'm saying is: work with Mother Nature.