Many therapies have been used including hyperbaric oxygen, dapsone, antihistamines (e.g., cyproheptadine), antibiotics, dextran, glucocorticoids, vasodilators, heparin, nitroglycerin, electric shock, curettage, surgical excision, and antivenom. None of these treatments conclusively show benefit. Studies have shown surgical intervention is ineffective and may worsen outcome. Excision may delay wound healing, cause abscesses, and lead to objectionable scarring.Dapsone, an antibiotic, is commonly used in the United States and Brazil for the treatment of necrosis. There have been conflicting reports with some supporting its efficacy and others have suggested it should no longer be used routinely, if at all. Antivenom
Use of antivenom for severe spider bites may be indicated, especially in the case of neurotoxic venoms. Effective antivenoms exist for Latrodectus, Atrax, and Phoneutria venom. Antivenom in the United States is in intravenous form but is rarely used, as anaphylactic reaction to the antivenom has resulted in deaths. In Australia, antivenom in intramuscular form was once commonly used, but use has declined. In 2014 some doubt as to antivenom effectiveness has been raised. In South America an antivenom is available for Loxosceles bites, and it appears antivenom may be the most promising therapy for recluse bites. However, in experimental trials recluse antivenom is more effective  when given early, and patients often do not present for 24 or more hours after envenomation, possibly limiting the effect of such intervention. Epidemiology
Estimating the number of spider bites that occur is difficult as the spider involvement may not be confirmed or identified.
Heat exhaustion is a severe form of heat illness. It is a medical emergency. Heat exhaustion is caused by the loss of water and electrolytes through sweating. The United States Department of Labor makes the following recommendation, "Heat illness can be prevented. Remember these three things: water, rest, and shade." Causes
Common causes of heat exhaustion include:
Hot, sunny, humid weather
Physical exertion, especially in hot, humid weather
Due to impaired thermoregulation, elderly people and infants can get serious heat illness even at rest, if the weather outside is hot and humid, and they are not getting enough cool air. Some drugs, such as diuretics, antihistamines, beta-blockers, alcohol,  MDMA (Ecstasy, Molly), and other amphetamines can cause an increase in the risk of heat exhaustion.Especially during physical exertion, risk factors for heat exhaustion include:
Wearing dark, padded, or insulated clothing; hats; and/or helmets (for example, football pads, turnout gear, etc.) Having a higher percentage of body fat
Dehydration
Fever
Some medications, like beta blockers and antipsychotic medicines

Signs and symptoms
Symptoms of heat exhaustion include skin tingling, nausea, dizziness, irritability, headache, thirst, weakness, vomiting, high body temperature, excessive sweating, pupil dilation, and decreased urine output.