Radiation is the transfer of heat between two objects in the form of electromagnetic energy. Radiation transfer occurs any time there is a temperature difference between two objects that are in view of each other. It is the process by which the sun transmits energy to the earth. It can be easily experienced by simply feeling the warmth of the sun while sunbathing. Conduction is heat transfer between two objects that are touching each other, for example, placing one's hand on a hot stove.
Convection is heat transfer from flow of a fluid or gas over an object.
Examples of convective heat transfer might be standing in front of a fan or placing one's hand into a flowing stream of water. In reality, evaporation is a combination of conduction and convection, but it is often considered a unique mechanism because it is so important in human heat dissipation. Sweating is the mechanism humans use to take advantage of evaporation heat loss. Hyperthermia is a condition where the body temperature is above normal. Heat stroke is a temperature-related illness that overwhelms the body's ability to dissipate heat.