One of the biggest problems of cameras is that they don’t “see” as well as the human eye. In fact it is all about the dynamic range. The eyes are able to see a large dynamic range, while the dynamic range of the camera is more reduced.
Moving to the Shade
One of the things you could do is to move to the shade. In this case it is alright if the harsh light comes through the window, because it becomes a softer light on the image. This means that as long as the subject is in the shadows, it is alright to have light on the photo.
Another possibility for you to use harsh light is to go for the silhouette of the subjects instead of the subjects themselves. You can achieve great results if you switch to manual exposure or if you change the metering mode so that it will measure from the background.
Burn the Background
It’s not always bad to have harsh light. In fact, you can create unique portraits with the right kind of light. For this you should choose a bright background that becomes entirely white when the light hits it. This way the portrait gets to the middle of the attention and there will be nothing to compete with it.
There are some tools you can use to make the light “friendlier”. One of these is a reflector. Make sure that the light bounces back to the subject. This way even the darker areas will have some light. If you are on a trip, it is a good idea for you have a folding reflector with you.
Flare on the Picture
While in the majority of the cases it is not good to have flare on the photos, if the effect is controlled, you can achieve unique images. All you have to do is to face the camera towards the light. The light should be coming from the edge of the frame. Another thing you may do is give up using the lens hood and go for the wide angle lens.
As you can see there is a lot that you could do with light; you just have to be in control of the situation and know in advance the kind of effect that you are going for. However, in some cases accidents can produce great pieces of art (and nobody has to know that it was an accident).