Your DSLR is a wonder of precision engineering, developed by serious-minded people who strive for excellence. Few people realise but the manufactures go to great length to eliminate Infrared light as you camera sensor is actually very sensitive to that wavelength.
Infrared is a slice of the electromagnetic spectrum invisible to humans. Ordinarily it's invisible to digital cameras too. However, it's possible to modify a digital camera to record this light by removing the IR filter from the front of the sensor. This needs to be done professionally by someone who knows what they're doing (it's not the sort of thing you want to try at home). Once the surgery has been performed on your camera you'll be able to shoot infrared images.
You need strong sunlight to shoot infrared effectively, making it a technique best left to summer rather than winter.
Why would you want too? Infrared photography has a unique style unlike any other form of photography. It only really works in bright sunshine. When it does green foliage turns almost snow white and blue skies darken virtually to black. It's a look you either love or hate (though that's arguably better than producing images that generate no feeling at all). Having your camera's sensor modified will cost you and is irreversible without incurring yet more expense (try www.lifepixel.com in the US and www.advancedcameraservices.co.uk in the Europe).
This image was taken at the Empire Mine in California
It's often cheaper to buy a camera that's already been modified second-hand (which will save your main camera for everyday photography). Another (if marginally less effective – and they don't work on every camera) way to experiment with infrared photography is to fit an infrared filter to your lens such as the Hoya R72.