That's why I either say "come to me" or say group up. I'll heal who I can but if I'm main heals like Mercy or Ana, I'm sticking with my tanks and I'm not going to chase you so you can carry. Come to me to get heals or stay within my vicinity
Whenever i have low health i say
" please heal me please heal me please heal me " i die next to the healer *inhales* *lets out long exxagerated disappointed sigh*