passion;  enthusiasm;  zeal
 zeal;  enthusiasm;  ardor;  ardour
 quantity of heat (e.g. in calories, BTU, etc.);  heat value;  calorific value;  (degree of) enthusiasm;  zeal;  passion
 white heat;  incandescence;  becoming excited;  getting heated (e.g. of a discussion);  reaching a climax
 to be delirious with fever;  to have a feverish dream; (fig.) to be crazy about something
 generation of heat;  (attack of) fever;  pyrexia
 heating;  application of heat
 impassioned speech;  fervent speech
 to become keen on;  to get passionate about
 heated (e.g. debate);  passionate
 having a crush on someone;  flushing
 love passionately;  ardent love;  devotion
 superheating;  overheating
 to become enthusiastic;  to have a crush (on);  to lose one's head (to);  to become earnest
 waste heat;  remaining heat;  residual heat
 teething fever;  developmental fever;  fever that brings with it an intellectual or psycho-developmental growth spurt
 to lose interest (in);  to grow less enthusiastic
 to check someone's temperature
 geothermal energy;  terrestrial heat
 geothermal energy;  terrestrial heat
 extreme passion;  wild enthusiasm
 thermal runaway;  overheating
 thermal energy;  heat energy
 remaining heat;  waste heat
 tertian malaria (causing a fever that recurs every second day)
 coldness and hotness;  cooling and heating;  indifference and enthusiasm;  prosperity and decline;  cold energy (e.g. in power generation)
 cold and heat;  chills and fever
 radiant heat;  photothermal
 degree of heat;  temperature;  enthusiasm
 the heat of food just after cooking
 preheat (oven, etc.);  warm up (engine, etc.)
 vaporization heat;  vaporisation heat
 medicine for reducing fever;  antifebrile;  antipyretic;  febrifuge
 heat death (i.e. of the universe)
 miliary fever;  (English) sweating sickness;  sweating disease;  polyhidrosis;  polyidrosis;  sudor anglicus
 becoming red hot;  red heat;  scorching heat;  running high (of emotions);  burning (with passion, enthusiasm, etc.)
 theory of heat;  thermal science;  thermology
 pharyngoconjunctival fever
 heat-sensitive paper;  thermal paper
 the heat of food just after cooking
 pyrolysis;  thermolysis;  thermal decomposition;  thermal cracking
 keeping the head cool and feet warm
 being lowered (of a fever)
 law of thermodynamics;  laws of thermodynamics
 Malta fever (variety of brucellosis caused by the bacteria Brucella melitensis)
 religious fervour;  religious enthusiasm
 pharyngoconjunctival fever
 warm (esp. from the fever of a sick person);  hot;  stuffy
 heat recovery;  thermal recycling
 baseball fever;  enthusiasm for baseball
 thermal fatigue (e.g. in structures);  heat exhaustion
 Rocky Mountain spotted fever
 heat of neutralization (neutralisation)
 heat sensitizer;  heat sensitiser
 thermophile;  thermophilic bacteria
 thermal expansion coefficient
 thermophilic bacteria;  thermophile
 heat fixing;  heat setting
 residual heat removal;  RHR
 potential heat;  residual heat
 thermal wax transfer printer
 cold political relations but hot economic relations (often said about China-Japan relations)
 hardener (catalyst in hardening thermosetting materials)
 Izumi fever (resembles scarlet fever)
 hay fever;  pollinosis (allergy to pollen)
 mononucleosis;  glandular fever