Are Ты Prepared For This?? :3

Oki, Heres a riddle, who every guesses it right I will Give u 20 Благодарности and I will Фан u, If Im not a Фан of u already(:

Heres the riddle:

I make Ты weak at the worst of all times. I keep Ты safe, I keep Ты fine. I make your hands sweat, and your сердце grow cold, I visit the weak, but seldom the bold. What am I?



Good Luck xD