Here are two links that answer your question in two different ways. Bottom line though, neither resistive or capacitive are doing based on the heat in your finger. Capacitive does it based on the electrical conductivity of your skin (so you can't wear gloves, use a stylus or fingernail), and the other by a circuit that is created by the pressure you exert (hence you CAN use gloves, stylus, etc).
OK, that's what i thought. The reason i asked is because my wife doesn't like my phones capacitive touch screen. She has nails and they just dont work LOL. So maybe holding out for a capacitive touch screen for her might not be the best thing??
I'd suggest a decent Resistive screen in that case, though I would really recommend investing in a decent screen protector. Some nails can manage to damage the naked screen
Similar issue here except she gets thrown off by the appearance of her fingernail. She uses her finger but it doesn't touch where she aims. Then she tries to push hard like it's a resistive screen. Iphone was a disaster for her. The sensitivity adjustment on the Blackberry Torch eased her pain, but capacitive screens are just plain difficult for her and painful for me to watch