Your physical health improves immensely, granting you the following benefits:

• Increase your Constitution score by 1, to a maximum of 20.
• You can add your proficiency modifier to Con Saves.
• When gaining temporary hp you can keep the last instance of temporary hp. (If you received 5 temp. hp last turn, you can now get another instance of temp hp on tip of that. But if you receive another instance you will not retain the 5 temp. hp)