MacBook case on hot summer days?

Hi,

You don't specify which MacBook you have, but I looked up several different Mac notebooks, and all had a maximum operating temperature of 95 degrees F. So you're already over that.

The metal skin of Mac notebooks acts to cool the inside components. To do that it must be exposed to air, and obviously a case is going to obstruct that, so a case is not a good idea.

If you put a thermometer over the keyboard of your Mac notebook while it's working, you'll find that heat escapes there too. A keyboard cover is going to seal that heat in, so again, not a good idea.

Some Mac notebooks don't have fans, so combining the insulating properties of a case and keyboard cover and the already too-high ambient temperature, means those notebooks don't have any defense against heat.

Bottom line: a case and keyboard cover are definitely recommended against.

Yes it will effect the cooling as it slows the progress of air through the interior and at least hinders air's contact with the actual case to a large degree. The hotter the day, the more heat the Mac holds in. Heat flows from hotter places to cooler places. If there is no cooler place for the heat to go, or it just can't get out, it just sits there. That's basic thermodynamics. Don't interrupt air flow in any way is the salient point.

If the case acts as a protective cover, it likewise acts as an insulator. Every layer of material layer over the case acts as an insulator. That is unless you find a cover made of thermally conductive material that has a way to offload the heat.

A keyboard cover should be fine in my opinion.

As for a case, just make sure ur case is not too thick and is not the type that traps heat. A good one should have vents/openings at the bottom and near the hinges (where air intake/out usually occurs for macbooks).

If you are using one of the latest Apple silicon (M1s & M2), I wouldn't worry much cause they have shown to be quite thermal efficient.

To be on the safe side, avoid being directly under sunlight.

I wouldn't use either on any day. Both will work against cooling your Mac.