Hello.
Sometimes and i use a Candle to enlighten the map after a potion usage, sometimes the candle hit me with my attack power or with the exactly HP i had healed seconds before.
Ex.: I used a potion that healed 10k life. Then i ate a burger and i received 10k damage. Or i use the candle and i received 4.5k damage.
This doesn't happen all the time, is random, but when happens while lvling it's dangerous.