How do you use heal kits?

Click on a player, then on Health

Apart from buying them or begging for them, where do I get them? Surely my hospital should make some

You can send a request to your facebook friends, each can give you 5 heal kits a day.
You can also ask for heals on your guild chat every hour.

It seems that the heal kits that I get from my guild are used extremely quickly as opposed to the heal kits that I got from the beginning. I had requested Heal Kits from my guild, had received 12 this morning and wanted to use it on a player. The player had 82% health and I clicked on "5% - 1kit" button.
The result was that the player went to 87%, which is correct, but that cost me 4 Heal kits, as I was now down to 8 Heal kits..??

That has got to be a bug..or..??

The button "1 kit" must use 1 kit.
Maybe there is a bug that displays a higher amount of kits that what you actually have. I will try to find out what happened.

The same thing happens to me too. I had a player that had 12 hours of injury left so I used 11 med kits but it only took 2 hours off. Work that out???

From what I see, you used 56 heal kits on your pillar (Joey) who was injured for 5days and reduced his injury by 56 hours.

When I pressed on the use one med kit sometimes it took multiple kits but only reduced by one hour. I just thought maybe kits from the guild were only a percentage of a full med kit or something. It confused me a little. I'll have to take note next time and see what occurs.

Ps I'm referring to guest_1442492993281 as this is my other team on my tablet.