How do you do "aid" on the 5e ogl sheet?

Hi all,  We en ou ter an issue with the caïd spell" and how to insert the +5 max ho and +5current hp.  Is there a way to add this 5hp to max hp but only for temporary use?  Like a ticking box somewhere on the sheet?  There's no hp mods bar to be visible in the parameters of the sheet like there are some for attacks or ac...  I'd prefer to keep Track of the +5 max hp somewhere instead of modifying the maxhp value, because we sometimes forget to take it off and then add some more hp on the next "aid" use...  How do you guys deal with this matter?  Thank you for your answer. 

We usually just rely on memory, but I just played around and it looks like if you change the hit point maximum field to something like "38 (33)", where the original max is in parenthesis. The graphical token bar linked to the hp attribute appear to still operate properly (honoring the first number: the temp max hp). Then it should be obvious when you go to cast it again what the original max was.