Do you already have an ssd installed? If you want your laptop to be faster it could be a great solution to improve performance. Just select an ssd, migrate your data onto it and replace your hard drive. This may even cool it down as there will be less moving parts. Of course, it's not the same as upgrading your cpu but as Nuclear101 said you may having heating issues and that may not be worth it as laptops run very hot to begin with.