1) Make SURE the Air Intake Duct has clearance around it, and is unrestricted from blockage.
( It's usually on the bottom of a laptop, with the Exhaust Duct on the side. Some models do have the air intake duct, and the exhaust duct on the side, however )
Although touted as a Laptop, it should not be used directly on your lap.
A flat hard surface of some sort is set on your lap first.
A laptop should Not be set directly on a bed, or couch, or carpet floor.
Always on a hard flat surface.
If your laptop has the air intake duct on the bottom, think about how close it is to the surface the laptop sits on.
Air is used to cool the hardware components inside a computer. The air flow must be unrestricted.
(Except for certain high-end gamer desktop computers. They may use a type of cooling that water, or refrigeration, or dry ice, or Nitrogen, may be used)
2) Run for 2 days continuously? If the AC adapter (Charger) is plugged into power, and into the laptop, yes.
Lower Processor power? I wouldn't ,unless this is an indication you are planning on using Battery power only.
Even with the laptop set to Power Saver mode, you won't get two days out of a laptop battery.
(Can I be wrong? Moi? Yes)
It would be an added bonus if you used a Cooling Pad.
This will ensure that the laptop is sitting on a hard flat surface, and will also add additional air for cooling.
There are economical models. Some models use a USB cable that plugs into the laptop, for their power.
Some models run off of batteries that are installed.
Examples from a quick search,
A laptop's enemy is dirt/dust, and heat.
(Also food crumbs, and drinks)
For additional questions please post in a Comment.