Do I have to worry about hardware when benchmarking algorithms?

I am trying to test algorithms by running simulations on my MacBook Air (2019). It takes time to run instances of the algorithms, and if I the execution up by algorithm instance, each instance takes about 2 hours. Now I have tried running all my instances over night, but I get some errors in my results. Assuming there is nothing wrong with my code, could the laptop be slowing down the further into computation it gets? I impose a time limit on the runtime of the algorithms, so could the first instance be run faster than the 10th because of the CPU temperature differences? There could be something wrong with my code. I haven't looked into it yet in detail. The question I am asking is do problems such as my computer slowing down like described above actually happen. Is this kind of stuff something I need to worry about, or can I just be agnostic to my machine and only worry about the code.