There is new legislation being considered by lawmakers in Michigan that may make it a felony to leave an animal in a car in conditions that might endanger its health. According to Mlive, the punishment is as follows:

A first offense would be punishable by up to a $350 fine and/or up to 45 days in jail. A second violation would be punishable by up to a $500 fine and/or up to 90 days in jail. If such confinement causes serious harm to an animal it's punishable by up to a year in prison and/or up to a $1,000 fine. And if the incident results in the death of an animal the punishment could be up to a $5,000 fine or 5 years imprisonment.

If the changes are made, Michigan would join 16 other states that consider it illegal to keep an animal in a car. However, a lot of the other 16 states only consider it a misdemeanor. You can read more about the legislation by clicking here.