(A) Thermogram (dorsal view) of Rhodnius prolixus during feeding on sheep blood (Tblood = 40°C) in an artificial feeder (on top). Horizontal dotted lines separate the different parts of the body, that is proboscis, head, thorax and abdomen. The vertical dotted line represents a transect along which the temperature of the surface of the insect’s body was measured. (B) Temperatures recorded along the transect designated in A. (Tblood = 40°C). (C) Impact of the difference between blood (Tblood) and environmental (Ta) temperatures on the body temperature of Rhodnius prolixus. (D) Average temperature of the proboscis, head, thorax and abdomen during blood-feeding in insects with severed dorsal vessels. (E) Relative levels of expression of HSP70 of sham-operated and dorsal vessel-severed bugs, measures 2 hr after fed on blood at 39°C. Asterisks: t-test, p<0.01, n = 5.