These are two problems you may encounter when growing cannabis indoors. If you set up your grow room to have the correct climate then the chances of you encountering either problem is less likely. That being said, either problem can affect any cannabis grow and it doesn't take much for heat stress or light stress to become a nuisance
When it comes to heat stress, cannabis will show the bulk of its symptoms relatively early and the easiest way to tell if your plants are heat-stressed is by checking the leaves as they may curl or wilt or in some cases have brown edges.
Light stress cannabis plants will display similar symptoms to heat stress in the sense that the leaves will be the most obviously affected areas. The leaves may begin to lose some of their green colors and appear lighter in color. 
Find out how to treat and prevent both of these growing pains in this week's PotCast.