how can i fix my renault megane 1.6 2003?

my car has been sitting on my drive for a week dueing the snowy conditions. Went to take her out, filled the car up with petrol, no problems, went for a drive and was going up a hill when the toxic fume warning light came on. since then the car will start up but then cuts out. we re-charged the car battery because that was low and checked the coils which have gone many a times. any ideas be gratefully welcomed